#precalculus

1 messages · Page 252 of 1

uncut mulch
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that gets you:
**-**4sqrt(6))/9 + 3

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since the stationary point is positive/negative sqrt 2/3
x-coords of the stationary points

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,w evaluate -4sqrt(6))/9 + 3

obsidian monolithBOT
delicate rivet
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where did the negative come from?

uncut mulch
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the question is how youre getting a positive

delicate rivet
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Heres my working, its really confusing but i basically found the stationary points and then tried to sub it ?

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oh shoot

uncut mulch
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bottom box

delicate rivet
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nvm

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thank you, potato_sweat that's my bad

grim sand
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Can I get help?

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Or is there a convo going on

willow bear
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there seems to be no convo going on here at the moment

grim sand
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Oh ok

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What am I looking for 😔 I’m lost

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@echo wagon can u help me

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Is it (3,0)?

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Can anyone help

novel cargo
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there is an interval where the graph decreases

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between 3 and 5 on the x axis the graph has a negative slope and the y value decreases as you move forward

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is that what you had in mind?

echo wagon
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What does decreasing mean @grim sand?

grim sand
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Going down

delicate rivet
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it should be the interval (3, 5)

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as that's when the gradient is <0, and make sure the brackets are round since the points aren't included

grim sand
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Huh

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Is this a different convo or for me..?

novel cargo
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for you

echo wagon
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It's for you, lol

grim sand
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Oh

delicate rivet
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if you look at the cubic graph, when x is < 3 the graph is going up yea?

grim sand
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@echo wagon plz translate 🥺

echo wagon
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Since you say it has to go down, where is it going down?

delicate rivet
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same with when x > 5, the only time the gradient/slope is negative is between 3 & 5

grim sand
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It’s going down at 3 on Y axis

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Yes

echo wagon
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At 3 on y axis ? What does that mean?

grim sand
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same with when x > 5, the only time the gradient/slope is negative is between 3 & 5
@amy.ames.aims#0827 I’m sorry but I don’t understand..

echo wagon
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Can you colour in the part that is going down?

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Like edit the picture

grim sand
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Oh

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Where is the shade

echo wagon
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Yeah exactly

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Now if you had to describe the x coordinates of that part of the graph, how would you do it?

grim sand
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0

echo wagon
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0?

grim sand
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Cuz the line start at 3,0

echo wagon
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There's literally no point on the entire graph where the x coordinate is

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0

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At least the visible part

novel cargo
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a line starting at 3.0 has x coord 0?

grim sand
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I’m confused

echo wagon
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(3, 0) which is the x coordinate?

grim sand
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The 0

echo wagon
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No

grim sand
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No

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The 3

echo wagon
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Yeah

grim sand
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And the Y is 0

echo wagon
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You really shouldn't get that wrong anymore

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And at what point does it stop going down?

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And what is the x coordinate of that point?

grim sand
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At (5,-4)

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5

echo wagon
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Yeah, and x coordinate is?

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Yes

grim sand
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Why are we only looking for X

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What about Y? It’s lonely

echo wagon
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So do you agree it is going down for 3 < x < 5?

grim sand
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Yes

echo wagon
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That's a fair point. But when we consider when a function has a specific property, we look at which part of the domain it has that property

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And the domain is the x values

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So how would you write the interval of the x values with 3 <x < 5?

grim sand
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(3,5)

echo wagon
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So that's the answer

grim sand
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Oh

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Oki

echo wagon
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That's the part of the domain where the function is decreasing

grim sand
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So when we looking for when the function is decreasing

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We only look for domain values?

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What if it’s increasing

echo wagon
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Well, everywhere else

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You always look at the domain

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If you ask WHERE DOES A FUNCTION HAVE SOME PROPERTY then you answer with a subset of the domain

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One reason for this is that a function can have multiple points with the same y value, so if you refer to the y values, it isn't clear which point you are talking about

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Whereas every point has a different x value

grim sand
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Oh bet

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Would I have to graph number 2 first?

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(-2,4)

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Is it right

echo wagon
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You don't know about derivatives yet? If not, yeah, graph it

grim sand
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What are derivatives

echo wagon
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Lol, so yes, graph it

grim sand
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I graphed it and looked at Domain only and got (-2,4)

echo wagon
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Well, I'll trust you then

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I didn't graph it so idk

grim sand
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Whut

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Ur not supposed to trust me

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I’m the idiot here

echo wagon
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Show me the graph then

grim sand
echo wagon
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Yeah, looks right

grim sand
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How do I find limit

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My teacher was supposed to teach me this but he doesn’t explain he just does the math

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Im dum
@235711131719232931...#8067 it’s ok I’m dumb too

delicate rivet
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My teacher was supposed to teach me this but he doesn’t explain he just does the math
@grim sand oof that's rough

grim sand
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Yes so I’m lost

viscid thistle
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My teacher was supposed to teach me this but he doesn’t explain he just does the math
@grim sand That's not good, at all

grim sand
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I just copy the work he does

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And not understand any of it

delicate rivet
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do you have a text book you can read through or anything?

grim sand
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No it’s online so it’s even worse

delicate rivet
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i can give you my notes if you'd like, i think we're doing the same course

grim sand
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Pre calc?

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Senior year

delicate rivet
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i have no idea im australian ://

grim sand
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Oh

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U understand these things tho?

delicate rivet
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it's yr 11 maths, but your questions look similar to what i did last term

grim sand
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I’m year 12 math

delicate rivet
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yep p much,,, i'm little slower since im yr 10 tho ://

novel cargo
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get a precalc book, I'm doing Larson's. Good IMO

delicate rivet
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I’m year 12 math
@grim sand the questions look the exact same O-O

grim sand
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Yes

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I was supposed to take this in year 11

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But

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My counselor said no

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So I had no math for 2 years

delicate rivet
grim sand
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So.. how do I find limits

delicate rivet
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here's the first part,,, i'll put together the answer sheet

grim sand
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Oh cool it tells me limits

delicate rivet
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uh depends on the denominator

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can i see the question?

grim sand
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Ok

novel cargo
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someone please check

grim sand
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i wish i could help

delicate rivet
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do you want the explanation or just the answer?

grim sand
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but i dont even know what a wave motion is

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explanation

novel cargo
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don't worry Jupiter

grim sand
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i like learning not a straight answer

delicate rivet
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ok sure;

novel cargo
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after two years of not doing math it will take a few painful weeks but then you'll feel much better

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just don't give up and be consistent with your daily practice

delicate rivet
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ok so with limits there are 3 different types of 'cases'

  1. where x is a constant number, (for example f(x) = 2)
  2. where the function has x terms but has a numerical denominator (eg 2x+3 --> the denominator is 1 in this case)
  3. where the function has x terms but has 0 for a denominator
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can you tell what 'case' yours is @grim sand ?

grim sand
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wait i lost my website

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ok i found it

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its 2

delicate rivet
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yep,

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so the next step would be to expand

grim sand
delicate rivet
grim sand
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how do you expand

delicate rivet
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i mean factorise

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sorry my bad ://

grim sand
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how do u factorise

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hop on vc and help? or just type

delicate rivet
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you take out 'like/similar terms' and group them together

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i'm sorry its nearly midnight here,,,, i don't want my mum to whoop my ass

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just ask away tho, i have plenty of time

grim sand
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3x^-x

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what do i take away

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the x?

delicate rivet
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yes!

grim sand
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so now its just 3^2

delicate rivet
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uh, not quite

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it'd be x(3x - 1)
because 3x^2 is equal to x * x * 3
and -x is equal to -1 * x

grim sand
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what does factorise mean

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it just means breaking the function apart?

delicate rivet
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it means to take out any common factors between your terms

grim sand
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@echo wagon plz dumb it down for me

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guess luna is afk

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so whats the answer to the equation? @delicate rivet

delicate rivet
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skdjhk i'm sorry i keep disappearing,,

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factorise and sub it the small number at the bottom

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wait is it an infinity sign?

grim sand
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this one doesnt have small number at the bottom

delicate rivet
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ok bad wording, the little symbols underneath 'lim'

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hmmm,,, i don't think i'm the best at explaining this for you,,,

grim sand
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what does that -> even mean

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im a visual learner

stuck lark
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@delicate rivet i recommend staying in alpha so your attention isn’t divided while you’re getting help

hallow thunder
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that means that x is approaching something

delicate rivet
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@delicate rivet i recommend staying in alpha so your attention isn’t divided
@stuck lark yea,,, that's really on me i took up too much

grim sand
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if ur getting help just ignore me

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i dont wanna disturb with ur learning

stuck lark
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i point it out mostly bc it’s rude to the helper when you’re not totally focused

grim sand
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yes that is correct

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So can someone free help me 🥺

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How do I solve limits

stuck lark
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not much computation needed, just note the polynomial degree & lead coefficient, then recall corresponding end behavior

grim sand
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What

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I’m dumb so I don’t understand any word u just said

stuck lark
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google: polynomial degree, lead coefficient, end behavior (of polynomial functions)

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and it’s really for jupiter to look this up (leave it jed)

hallow thunder
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i was going to suggest how i solve them

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nvm

grim sand
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Ok

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What do I do after searching it up

stuck lark
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study it

grim sand
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This isn’t helping

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Cuz I can’t ask it questions

stuck lark
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once you read and try your best to study, then you can come back and ask questions

delicate rivet
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i point it out mostly bc it’s rude to the helper when you’re not totally focused
@stuck lark You're right, and I apologise. I bit off more than I could chew for a short period of time bunHide

stuck lark
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thanks @delicate rivet vvWink but the apology should go to anubis

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and jupiter if you feel like you can attempt the question after studying then here, to start you off

not much computation needed, just note the polynomial degree & lead coefficient, then recall its corresponding end behavior

grim sand
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What is computation

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Actually

delicate rivet
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computation is referring to your working,

grim sand
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Can someone tell me what this type of equations are called so I can watch YouTube videos

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The limits and stuff

delicate rivet
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like it's saying not a lot of thinking is required

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have you tried khan academy?

grim sand
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I hate that

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It makes me more confused

delicate rivet
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like the app?

grim sand
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Tried it freshman year it didn’t work out well

delicate rivet
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i'd suggest your teacher then, or a tutor since they can help you with specific questions you have

grim sand
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What is this type of equations called

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My teacher can’t teach so he’s useless

sour wagon
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@grim sand take one word in what @stuck lark wrote at the time and try to unwrap it and see what it means. You kind of have to go through this because mathematicians use these to somehow make sense of it all. (Imagine some numbers being written in arabic, some in Kanji and some in roman numbers, we need common language for them)

grim sand
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Oh

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So it’s like different math languages but we need a specific one from each to combine to get to know the one I’m looking at?

sour wagon
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well no but your example is even better. Yeah, each formula or even sentences like the one the guy wrote to you, they represent a bag of math that will solve your problem

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but you first have to go through the trouble of understanding them

grim sand
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Okay bet

delicate rivet
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My teacher can’t teach so he’s useless
@grim sand surely theres more than one math's teacher in your school? what about the math's co-ordinator?

grim sand
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Got any videos that are spot on or do I have to look for myself

delicate rivet
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idk, i'm sorry mate

grim sand
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@grim sand surely theres more than one math's teacher in your school? what about the math's co-ordinator?
@amy.ames.aims#0827 idk what that is but we only got 1 pre calc teacher here

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And it’s online so it’s harder

delicate rivet
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ooo, what about the other people in your class?

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you could always shoot him an email asking for 15 minutes of one on one?

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that's what worked for me when I fell behind a bit

grim sand
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Talking to him is a no man I don’t understand anything he says

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And 90% of my friends r as clueless as me

delicate rivet
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what about the people doing well? would they be willing to help?

sour wagon
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I think I used to be in similar condition when it comes down to education as you @grim sand where are you from?

grim sand
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NC

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North Carolina

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Bum teachers

delicate rivet
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that's in america right?

grim sand
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Yes

sour wagon
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oh I am from Eastern Europe

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well the world is a small place 😄

delicate rivet
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ohh k tyy

grim sand
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what about the people doing well? would they be willing to help?
@amy.ames.aims#0827 no clue I’m too scared to ask them cuz idk them

delicate rivet
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hmmm first place i'd start is factorisation videos then?

sour wagon
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come on man that's at least 500% better and faster to get something if you can talk to someone who knows it and can talk to you in person

delicate rivet
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you need to have a strong grasp of algebra before you can tackle any of the graphing stuff

grim sand
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I don’t know how to get in contact with them

delicate rivet
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^^ what allione said

grim sand
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We use zoom and zoom doesn’t let me email them

delicate rivet
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email, zoom, stay behind after class

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dm them,

grim sand
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U can dm from zoom?

sour wagon
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go to them when you see them goddamnit they'll might even thank you for asking for help

grim sand
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go to them when you see them goddamnit they'll might even thank you for asking for help
@sour wagon 😔🤚🏻

delicate rivet
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U can dm from zoom?
@grim sand yes? i think so

grim sand
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Idk it’s my first year using zoom

delicate rivet
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click alt h / open chat and toggle down for the person you want

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idk either man i only use it for co-curriculars,,, we use microsoft teams

grim sand
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My pre calc period ended 2 hours ago I’ll do it tmr hehe

delicate rivet
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2hrs? skjhkj aight u got the rest of the day to start learning the basics to differenciation calc

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Glll

grim sand
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Thank u

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I’m learning polynomials rn

delicate rivet
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like on your own or in class?

grim sand
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On my own

delicate rivet
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oo thats a good start,, just keep at it

novel cargo
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trying to plot this in desmos

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what am I doing wrong?

willow bear
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use another letter for the input of f and z

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and then in the table put f(g) and z(g) for your columns

novel cargo
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wow

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thanks

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it shows that tan(x) is just pi/2 late compared to -cot(x)

austere void
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are you sure it isn't pi/2 early? 😃

jade iris
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Im just having a brain fart bc this is old material to me but how would you find the y=ab^x form of the exponential function f(x)=5^x8^x ( I know the answer a=1 and b=40 I dont understand how to work it backwards)

blissful ridge
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$l^k\cdot m^k=(l\cdot m)^k$

obsidian monolithBOT
blissful ridge
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@jade iris

jade iris
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@blissful ridge why is a=1?

blissful ridge
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Use the identity, I gave you and tell me what you get?

jade iris
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40^k

blissful ridge
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$40^k=1\cdot 40^k$

obsidian monolithBOT
jade iris
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is it because 1 is considered an initial value so there isnt but the intial value cannot be zero which would the expression not valid?

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@blissful ridge

blissful ridge
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You can multiply 1 so any given expression and it won't change the value

jade iris
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ah ok so what would be an example of a would not be 1 @blissful ridge

blissful ridge
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$2\cdot 39^k$

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$2\cdot 39^k$

obsidian monolithBOT
jade iris
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so now a=2 and b=39

blissful ridge
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Yeah

jade iris
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Yep get it now @blissful ridge thank you!

lucid owl
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Y=1/3f(1/2x+1)

viscid thistle
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Parentheses?

hushed sorrel
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i think it looks correct

viscid thistle
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If you typed it in exactly like that then it’s not right

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(1/2)(x+1)

regal kernel
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A cubic function generally has the form
f(x) = ax^3 + bx^2 + cx + d.
If we know that for some x-value x = p we have
f(p) = 0,
then it must be true that x − p is a factor of f(x). Since we are told that
f(3) = 0,
we know that 3 is a factor

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@viscid thistle Can you help verify the last statement of "3 is a factor"?

viscid thistle
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Why was I tagged with this question

regal kernel
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you might be able to help me since you have, "advanced" as a tag

viscid thistle
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Can you... not tag people without a good reason

regal kernel
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... alright man

swift flume
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doesnt it mean f(3) = 0?

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like, (x-3) is a factor of the function

regal kernel
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yes it does mean that f(3) = 0

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i added the bolded part to the statement

swift flume
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yeah

regal kernel
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do you think 3 is a factor?

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or what are they trying to ask there

swift flume
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I'm not very good at this either but I think that means

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(x-3) is a factor of the function

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like, if you divide the equation by (x-3) the remainder would be 0

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cuz of the factor theorem

regal kernel
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hmm alright

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so instead of 3, it would be more accurate to say, "x-3 is a factor"?

viscid thistle
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Yes, this looks like a restatement of factor theorem

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But for a particular value of 3

regal kernel
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thanks

viscid thistle
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And yes x-3 is a factor sounds better to me

willow stream
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Hey can someone help explain to me an identity

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$(cos(x))^2 == 1-sin^2(x)$

obsidian monolithBOT
willow stream
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wouldn't it be instead

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$1+cos(2x)/2$

obsidian monolithBOT
willow stream
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Okay

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This is the pdf I am using

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for trig identities

lime bolt
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well i guess that does also work

willow stream
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which is easier though

lime bolt
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they are equivalant anyway

willow stream
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I figure sin^2

lime bolt
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actually u need to divide the 1 by 2 as well

willow stream
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Yes my bad

lime bolt
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do u know the expansion of cos(2x)

willow stream
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2cos(x)?

lime bolt
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no.....

willow stream
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oh the formula

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1/2 + cos(2x)/2 ?

lime bolt
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no that isnt the expansion

willow stream
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Can you explain it to me please

lime bolt
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it is cos^2 -sin^x

willow stream
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Oh

lime bolt
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do u know expansions of sin(x+y) and cos(x+y)

willow stream
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$2sin((x+y)/2))cos((x+y)/2)$

obsidian monolithBOT
willow stream
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To be honest, off the top of my head I do not

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I can off of a formula sheet but that isn't exactly knowing it

lime bolt
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why do u keep using these ones

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this is a corollary of the main ones

willow stream
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Is there a better resource?

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if you don't want to open the file which I understand i'll send a screenshot of it

lime bolt
willow stream
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ohh I see

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I see my error with the org problem

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I was supposed to use the Pythagorean identity

lime bolt
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you should prove that identity

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using the definitons if sinx and cosx

willow stream
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Okay so for instance: $If sin^2+cos^2 = 1 then cos^2 = sin^2 - 1$

obsidian monolithBOT
willow stream
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Yeah the unit circle

ember crane
weak sierra
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@ember crane well cot = 1/tan so yes

ember crane
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but the square part is also applicable right?

viscid thistle
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yeah

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@ember crane

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from cot(x)=1/(tan(x)) you can square both sides to get to that conclusion

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@ember crane

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$cot(x) = \frac{1}{tan(x)}$ then we have, $cot^{2}{x} = (\frac{1}{tan(x)})^{2}$ then we get $cot^{2}{x} = \frac{1}{tan(x)}\frac{1}{tan(x)}$ then finally, $cot^{2}{x} = \frac{1}{tan^{2}{x}}$

obsidian monolithBOT
viscid thistle
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...

ember crane
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wow.... thnks

tardy ridge
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why does 1 question need to be answered 3 times.

viscid thistle
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Yeah like

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I have no idea

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why does 1 question need to be answered 3 times.
2 times

ember crane
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nah, its 3 XD

viscid thistle
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Also

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\tan(x) \sin(x) \cos(x)

ember crane
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1 from CEO of your data, 1 from Al3dium aand one from Sasuke Uchiha

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yes sir, thnk u very much 😄

viscid thistle
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Ceo of your data didn't answer the "but the square part is also applicable" lol

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So it's 2

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but i explained with the most detail 😎 me acting liking that matters

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...

ember crane
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lol XD

viscid thistle
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Someone ban him

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now

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wanna chess battle ✊

mighty onyx
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$4\log x-3\log(x^2+1)+4log(x-1)$

ornate wolf
obsidian monolithBOT
mighty onyx
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any one know how to rewrite this into a single logarithm?

uncut mulch
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power law and then sum/difference to product/quotient

mighty onyx
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huh?

uncut mulch
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those reference the log laws you would need to apply

mighty onyx
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so I don't just simplify it?

uncut mulch
#

simplificty is subjective here

mighty onyx
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I think I should rewatch the lecture tbh

uncut mulch
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$a\log(b) = \log(b^a)$ would be the power law

obsidian monolithBOT
uncut mulch
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which you should apply to all your terms if you intend to combine them into a single log

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as the other law(s) you would need to apply are: \
$\log(a) + \log(b) =\log(ab) \
\log(a) - \log(b) =\log\br{\frac ab}$ \
(for $a,b > 0$)

obsidian monolithBOT
mighty onyx
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so for mine it would be $x^4+x^6+1^3+x^4-1^4$ then simplify it. Log is not part of the final answer he says.

obsidian monolithBOT
uncut mulch
#

no

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that's not how exponents work

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$\fdream$

obsidian monolithBOT
uncut mulch
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and applying the power law doesn't make the log dissapear

mighty onyx
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I think he means after it's simplified into a simple logarithm don't put the log into the answer bar

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like if it's $logaB+C$ just put $aB+C$

obsidian monolithBOT
uncut mulch
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um put proper parentheses please

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regardless you're applying the proper steps in combining the logs

mighty onyx
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ok

uncut mulch
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refer to the power law above and tell me what you have after applying it

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don't bother expanding them btw. leave it in exponent form.

low owl
#

I'm sitting here trying to memorize the unit circle lol my brain is saying no

viscid thistle
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Don’t try to memorize it

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try to memorize the methods that created it

#

So you can logic your way through piecing it together yourself

low owl
#

will do

mighty onyx
#

Nvm got it

#

$(x^4(x-1)^4)/((x^2+1)^3)$

obsidian monolithBOT
delicate rivet
#

I got (5x^3/2)/2, is that right? and how would you simplify it even more?

blissful ridge
#

Looks alright to me
And simplification is subjective

uncut mulch
delicate rivet
#

how would you simplify it? -ty btw

uncut mulch
#

\verb|(5x^3/2)/2| reads as $\frac{\br{\frac{5x^3}{2}}}{2}$

obsidian monolithBOT
uncut mulch
#

but if you intended $\frac{5x^{\frac32}}{2}$ represented by \verb|5x^(3/2)/2| in plain text, that would be simple enough

obsidian monolithBOT
delicate rivet
#

hmm yea i understand, but are there any that match one of the answers?

#

i think i'm simplifying it wrong or something,,,, i can't get their answer

uncut mulch
#

exponent - radical laws

#

what would x^(3/2) be as a radical?

novel cargo
#

x^1 * sqrt(x) = x^1 * x^1/2 = x^3/2

delicate rivet
#

sorry but what's a radical?

#

oh nvm i had to look it up

#

x^(3/2) = (root x)^3 yea?

#

x^1 * sqrt(x) = x^1 * x^1/2 = x^3/2
@novel cargo ohhhhh thank you!

uncut mulch
novel cargo
#

true

delicate rivet
#

how do we know when the gradient of a graph is defined?

willow bear
#

when the function being graphed is differentiable

#

i.e. when the limit $\lim_{h \to 0} \frac{f(x+h)-f(x)}{h}$ exists for whatever values of $x$ we care about

obsidian monolithBOT
novel cargo
#

what is the gradient of the graph?

delicate rivet
#

i think it's slope in america?

novel cargo
#

ahh, thanks

delicate rivet
#

i.e. when the limit $\lim_{h \to 0} \frac{f(x+h)-f(x)}{h}$ exists for whatever values of $x$ we care about
@willow bear ohhhh thank you

obsidian monolithBOT
novel cargo
#

well there are cases when the limit exists but the slope does not

#

or is not differentiable

delicate rivet
#

wait how come x^1/3 isn't differentiable?

willow bear
#

it's not differentiable at 0 because the limit up there with f(x) = x^(1/3) and x = 0 works out to +∞

delicate rivet
#

oHHHh thank you sm

willow bear
#

you have a vertical tangent line at 0

delicate rivet
#

gotcha,,, tytyyyyyy

novel cargo
#

like abs(x) at zero is not differentiable but has a limit

willow bear
#

no, $\lim_{h \to 0} \frac{|0+h| - |0|}{h}$ does not exist.

obsidian monolithBOT
delicate rivet
#

abs(x)?

novel cargo
#

|x|

delicate rivet
#

ohh

willow bear
#

az, what you might have been trying to say is that the absolute value function is continuous but not differentiable at 0

novel cargo
#

yeah,

willow bear
#

which is true, but (a) tangential to what i was saying and (b) poorly phrased on your end

novel cargo
#

ahaha

#

I'm poorly phrased, baby yoda

#

what you expect?

delicate rivet
#

does anyone have an example problem of "find the tangen of [x] curve at point [z]?

#

i need to practice and I've already done all the example problems in my book O-O

willow bear
#

oh sure i can make you some if you want

delicate rivet
#

yes please!

willow bear
#

how many do you want

novel cargo
delicate rivet
#

uh what every suits you, but maybe at least 3?

willow bear
#

ok

delicate rivet
#

wait do you have any problems about finding the equation of the tangent (i don't think finding the gradient of the graph will be on the exam)?

willow bear
#
In each exercise, find the equation of the tangent line to the graph of y = f(x) at x = c.

[1] f(x) = 100x/(x^2 + 1); c = 2
[2] f(x) = cos(x) - 11x; c = 2π
[3] f(x) = e^(5x) + cos(2πx); c = 3
[4] f(x) = sqrt(x)/(x+7); c = 9
[5] f(x) = sin(2πx^2); c = 3/2
delicate rivet
#

ty!

delicate rivet
#

is 1) y=8(4x-3) & 4) (-3x+75)/1696?

willow bear
#

(1) doesn't match my answer key

delicate rivet
#

oh shoot, let me try again

willow bear
#

and neither does (4)

delicate rivet
#

hmm i'll go read over my textbook and try again then

#

ty for this

#

is 1) y = 8(2x+1)?

willow bear
#

no

delicate rivet
willow bear
#

f'(x) is wrong

#

100x is not a constant

delicate rivet
#

oH, ty let me try that again ;-;

#

um,,, how would you find the derivative of 1) quickly?

willow bear
#

quotient rule

delicate rivet
#

I think my teacher skipped over that? we only learnt the chain rule

#

could you go over it with me please?

willow bear
#

wait you didn't learn the quotient rule??

#

ok then you'll have to use product & chain

delicate rivet
#

For f’(x)

willow bear
#

very first line, you mis-parenthesized 100(x^2+1)

delicate rivet
#

dont mind the bad handwriting,

willow bear
#

lol

#

that's bad handwriting?

#

i've seen way worse

#

anyway

#

lemme check this

#

,w d/dx 100x/(x^2+1)

obsidian monolithBOT
willow bear
#

aight yeah you're good

delicate rivet
#

oh yea, sorry about my brackets they're just there so i can write in the multiplication symbol so i remember better

willow bear
#

$100 \times x^2 + 1$ reads as $100x^2 + 1$ and not $100(x^2+1)$

obsidian monolithBOT
willow bear
#

order of operations

delicate rivet
#

oof yea you're right,,, my bad, i'll fix that

#

is 1) -4(3x+4)?

willow bear
#

no

delicate rivet
#

If youre not busy ofc

willow bear
#

y - 40 = -12(x-2)

delicate rivet
#

do you not then bring the -40 to the other side creating
y = -12(x-2) -40 ?

willow bear
#

no such thing as "bringing" anything to the other side

#

also, you wouldn't go from z - 6 = 11 to z = 11 - 6 would you?

delicate rivet
#

ok bad wording, do you not add 40 to both sides?

willow bear
#

add 40 yes

#

but you did not do that

delicate rivet
#

oH skdjhdkj stupid mistake
it then you would expand and factorise for the answer correct?

willow bear
#

you don't really need to factor the 4 out tbh

delicate rivet
#

really? doesn't the answer need to be in the simplest form?

#

the answer is -12x + 64
or
-4(3x-16) right?

willow bear
#

-12x + 64 is honestly much simpler than -4(3x-16)

#

it's slope intercept form

delicate rivet
#

ohhh right right

#

thank you so much for your help,
||i can't believe it took that long for me to do one question 😭 - the amount of careless mistakes i made-||

willow bear
#

yeah the careless algebra mistakes will cost you a lot of time

delicate rivet
#

ikkk it's one of my worst habits,,,,, idk how to fix it tho,,, i just hope i get enough sleep the day before the exam

willow bear
#

do algebra but slowly

viscid thistle
#

how to fix algebra mistakes 101 : do more problems related to simple algebra and a lot of them

somber folio
willow bear
#

you... just do? $\frac{\sin(x)}{x \cos(x)}$ can be broken down into $\frac{\sin(x)}{x} \cdot \frac{1}{\cos(x)}$ just fine

obsidian monolithBOT
somber folio
#

ohhh okok thanks

lime bolt
#

lol what was confusing about that sully

grim sand
#

Is G(X) the same thing as F(X)?

lime bolt
#

what is f(x)

grim sand
#

Uhh

#

F (x) = ?

#

Do they mean the same thing just different letters or no

lime bolt
#

i dont know what you are on about

novel cargo
grim sand
#

I don’t know either anymore

novel cargo
#

oh, sorry, didn't realize conv was going on

viscid thistle
#

f and g are names of functions, you can also call it apple

#

apple(x)

grim sand
#

So it is the same thing

lime bolt
#

what is the same thing?

viscid thistle
#

yes

grim sand
#

F and G

#

yes
@viscid thistle thank u

viscid thistle
#

They are both functions

lime bolt
#

well it depends on what f(x)

grim sand
#

So when I solve for F(x) I can also solve for G(x) the same exact way

lime bolt
#

if f(x) isnt g(x) then they arent the same thing

grim sand
#

Right

#

It doesn’t tell me what F(X) is, only g(x)

lime bolt
#

if and only if f(x)=g(x)

viscid thistle
#

He wasn't sure whether calling a function f or g was the same thing

lime bolt
viscid thistle
#

The name of a function is arbitrary

willow bear
#

@grim sand g is just a name

#

sometimes when you have two or three functions they are called f, g and h

#

but it's not a hard rule

#

it's like calling a variable y instead of x

grim sand
#

So when I try to sketch piece wise functions it’s usually F(x) but this equation is G(x), I’m asking if I can sketch it the same way as I sketch F(x) or is there something different

novel cargo
#

the name of the function has no bearing on its graph

#

the name is arbitrary

#

the equation that defines the function makes it clear how to plot the graph

#

also the domain

viscid thistle
#

What if you name your function f(x)=69(x)=5x

grim sand
#

Lost I am

#

Understood I’m not

viscid thistle
#

Ignore anything I said

#

(just stop answering the question)

grim sand
#

Same thing or not the same thing

novel cargo
#

are the equations that define G(x) and F(x) the same?

viscid thistle
#

f=G

novel cargo
#

also the domains?

grim sand
#

Yes

novel cargo
#

then they are the same

grim sand
#

Ok

#

Thanks

novel cargo
#

the could be Z(x) or Barbie(x)

viscid thistle
#

If f(x)=G(x) for any point x then f=G

novel cargo
#

any tips?

viscid thistle
#

Start by rewriting it as tangent

#

Then rewrite the tangent

willow bear
#

make a right triangle#

#

seriously make a right triangle

#

make two of its sides 3 and 8 in a way that gets you an angle with sine 3/8

novel cargo
#

oh, rewrite the inner piece as an algebraic expression?

viscid thistle
#

He can just use $\cot(\arcsin(y))=\frac{\sqrt{1-y²}}{y}$ too

#

Oh I was going for an algebraic way

obsidian monolithBOT
viscid thistle
#

That works too

novel cargo
#

👍

willow bear
#

bruh ok everyone kind of just went and ignored me

viscid thistle
#

bruh ok everyone kind of just went and ignored me
Your method leads to what Al suggested

#

Yeah

viscid thistle
#

Yo we have this activity and thw teacher didnt even teach it

#

How can J find the equation of the ellipes with the center of origin (0,0) the foci have coordinates (4,0) and (-4,0) and a vertex is at (-5,0)

blissful ridge
#

In the general equation of ellipse
$\pm ae=foci$ and vertex is $\pm a$

obsidian monolithBOT
blissful ridge
#

And we have a relation
$b^2=a^2(1-e^2)$

obsidian monolithBOT
viscid thistle
#

Oh its conic section of an ellipse

mighty onyx
#

$ln (1+x^2) + \frac12\ln x - \ln (\sin x)$ would this rewritten be
$((1+x^2)x^1_2/sin(x))$

obsidian monolithBOT
viscid thistle
#

almost.

#

where did the ln go

mighty onyx
#

he says to not put it in only the numbers after it.

nova wedge
#

question regarding the x and y switch

#

can someone remind me why the y wouldn't go on top?

#

is that because we are not dividing by 1/y?

viscid thistle
#

he says to not put it in only the numbers after it.
@mighty onyx what?

#

@nova wedge taken channel, please move

nova wedge
#

@viscid thistle I'm sorry? Where do I move to?

mighty onyx
#

yeah like it's set up ln A, A= BLANK

#

or Log A, A= Blank

#

here is an example

#

I need to rewrite $ \log_2x + 5\log_2y +-3\log_2z$

obsidian monolithBOT
mighty onyx
#

and the right answer for some reason is $xy^5/z^3$

obsidian monolithBOT
mighty onyx
#

I have no idea why he removed the Parenthesis

#

I.. I hate it

viscid thistle
#

Like wtf

#

$\log_2(x)+5\log_2(y)-3\log_2(z)=\log_2(\frac{xy⁵}{z^{3}})$

obsidian monolithBOT
viscid thistle
#

And that's it

#

The log doesn't get removed

#

And if it really shows (xy⁵)/(z³) as an answer, the book is wrong

#

@mighty onyx

mighty onyx
#

I'm having a mental breakdown why did he do it like this

#

broke Doctorate Holder

viscid thistle
#

Post a pic

#

If they really did it, they are just wrong

mighty onyx
#

But This one

viscid thistle
#

Ahhh seee

#

They say: log(A), what is A?

#

Then they are correct

#

It is not

mighty onyx
#

I am trying to think of what he put for the fraction exponent

viscid thistle
#

They also even note: ln is not part of your answer

mighty onyx
#

because it should be ((1+x^2)x^1_2/sin(x))

viscid thistle
#

Wdym by _2?

mighty onyx
#

yeah that's what I told yall

#

to make it $b^1_2$

obsidian monolithBOT
viscid thistle
#

They have x^1_2 as an answer?

mighty onyx
#

how do you do fraction exponents

viscid thistle
#

x^(1/2)

#

Not x^1/2

#

Is that where you fell off

#

Probably yeah

#

You should have written x^(1/2) and not x^1/2

mighty onyx
#

yep I changed the whole answer to $(1+x^2)x^(1/2)/(sinx)$

obsidian monolithBOT
viscid thistle
#

On latex it is x^{1/2} or x^{\frac12}

mighty onyx
#

I think he did this problem wrong because wouldn't $Log_5(125)=3$

echo wagon
#

It makes a lot of sense that $\frac12$ would work, and yet I never realized it

obsidian monolithBOT
viscid thistle
#

Yeah

#

It only works with numbers though Luna

echo wagon
#

Ah, otherwise it looks like a different function

viscid thistle
#

@mighty onyx yes log_5(125)=3

#

Because 125=5^3

mighty onyx
#

okay so I think he typo'd because all the other ones I put were right but it says it's wrong. What if he put like 2 lol

viscid thistle
#

Wdym by what if he put like 2

mighty onyx
#

as a typo idk what he put

#

know this one has me confused to

#

Use the Laws of logarithms to rewrite the expression $\ln\left(\frac{x^4\sqrt{x-1}}{3x-14}\right)$ in a form with no logarithm of a product, quotient or power. After rewriting we have $A\ln x+B\ln(x-1)+C\ln(3x-14)$

obsidian monolithBOT
mighty onyx
#

we need to find A,B, and C

viscid thistle
#

Yeah

#

So basically wants you to use the $$\log(a\cdot b)=\log(a)+\log(b)$$
$$\log(\frac{a}{b})=\log(a)-\log(b)$$

obsidian monolithBOT
viscid thistle
#

@mighty onyx

mighty onyx
#

so for B would it turn into (x/1)

#

he says we need to find the constant for each one

viscid thistle
#

$\log(ab³)=A\log(a)+B\log(b³)=\underbrace{1}{A=1}\log(a)+\underbrace{3}{B=3}\log(b)$

#

This is an example of how it'd be done

mighty onyx
#

forgot a $

viscid thistle
#

True

obsidian monolithBOT
viscid thistle
#

Because you know $\log(a^b)=b\log(a)$

obsidian monolithBOT
viscid thistle
#

Logarithmic laws

#

@mighty onyx hello?

#

Do you need me to explain even further?

mighty onyx
#

I'm still here just trying to work it out now

viscid thistle
#

Okay

#

Look at the example for reference, tag me when you have a doubt

mighty onyx
#

okay so a=4 b=1/2 and c=-1

viscid thistle
#

Correct. @mighty onyx

mighty onyx
mighty onyx
#

would we use the same way for $\log_2\left(32(a+1)^{-4}\right)$ rewritten as

obsidian monolithBOT
mighty onyx
#

$A+B\log_2(C)$

obsidian monolithBOT
viscid thistle
#

Yeah

#

Why not

mighty onyx
#

for B it's -4

viscid thistle
#

Yes

mighty onyx
#

but what happens to the 32?

viscid thistle
#

Express 32 in terms of 2

#

And remember that $\log_a(a)=1$

obsidian monolithBOT
mighty onyx
#

32 in terms of 2? like 16

viscid thistle
#

81 in terms of 3 would be 3³

#

32 in terms of 2? like 16
32 can be expressed in a way where the 2 is the base raised to some number

#

As i did with 81

mighty onyx
#

oh so it would be for 32 2^5

viscid thistle
#

Yes.

mighty onyx
#

and know c

viscid thistle
#

Do you know how to continue remembering that $\log_a(a)=1$

obsidian monolithBOT
mighty onyx
#

but what is your way

viscid thistle
#

After doing 32=2⁵, $\log_2(2⁵)=5\underbrace{\log_2(2)}_{1}=5$

obsidian monolithBOT
viscid thistle
#

You can use your logic to know why log_2(2) is 1, think of it this way, to what should you raise 2 to receive 2 as an answer.

#

@mighty onyx

mighty onyx
#

yeah

viscid thistle
#

All good then?

olive quartz
#

Find the solution of the following equation whose argument is strictly between 180 degrees and 270 degrees.
Round your answer to the nearest thousandth.

#

$z^5=-243i$

obsidian monolithBOT
olive quartz
#

I'm not really sure of how I would do this

#

I think the modulus would be -3 though

#

as for the angle I have no clue

hallow thunder
#

@olive quartz Hint: $-i = e^{i\cdot 270^{\circ}}$

obsidian monolithBOT
viscid thistle
#

Can i get help with deriving powers?

olive quartz
#

what

hallow thunder
#

Do you know euler's formula?

olive quartz
#

$re^{i\theta}$

obsidian monolithBOT
hallow thunder
#

yeah

lime bolt
#

radians is better than degrees here

mighty onyx
#

@viscid thistle I am still having trouble finding c

hallow thunder
#

yeah but the answer is meant to be in degrees

#

i think

olive quartz
#

how can we use the formula here?

mighty onyx
#

oops sorry

hallow thunder
#

If you look on the complex plane, $-i$ is $270^{\circ}$ anticlockwise rotation from the center and has a magnitude (length) of 1 from the center. Therefore it can be written as $e^{i \cdot 270^{\circ}}$

olive quartz
#

oh

obsidian monolithBOT
olive quartz
#

oh yeah

#

that makes sense

hallow thunder
#

Ill let you figure out the rest of how to do the question 🙂

olive quartz
#

ok

#

thanks

hallow thunder
#

np

viscid thistle
#

@viscid thistle I am still having trouble finding c
@mighty onyx repost it

mighty onyx
#

$ \log_2\left(32(a+1)^{-4}\right)$

obsidian monolithBOT
mighty onyx
#

$A+B\log_2(C)$

obsidian monolithBOT
viscid thistle
#

wait you can't find C? it is pretty much the same as the other ones we've done

#

let's see if it gets clarified with this

#

remember what we said $\log(a\cdot b)=\log(a)+\log(b)$ right so on this case, a and b are: $$\log_2(\overbrace{32}^{a}\cdot \overbrace{(a-1)^{-4}}^{b})$$

obsidian monolithBOT
mighty onyx
#

so if Log(c) = log(a+b)?

#

no that's not it

viscid thistle
#

what?

mighty onyx
#

is*

viscid thistle
#

okay

#

would you be able to express this as a sum of logarithms $\log(4\cdot u^{3})$?

obsidian monolithBOT
viscid thistle
#

@mighty onyx

mighty onyx
#

$\log4 + 3\logu$

obsidian monolithBOT
stuck lark
#

\log

viscid thistle
#

okay

#

so

obsidian monolithBOT
stuck lark
#

$\log(4)+3\log(u)$

obsidian monolithBOT
mighty onyx
#

yeah thx

viscid thistle
#

$\log(a\cdot b)=\log(a)+\log(b)$ using a substitution with the $u:= a-1$
$$\log_2(32\cdot \overbrace{(a-1)^{-4}}^{u^{-4}})=\log(32\cdot u^{-4})$$ would you be able to express this as a sum of logarithms

obsidian monolithBOT
mighty onyx
#

$\log 32 and -4\log (a-1)$

obsidian monolithBOT
viscid thistle
#

replace the "and" with a sum and you just found C

#

and well, simplify the log(32) too

mighty onyx
#

I'm still confused I think

#

how can the constant be the sum of log(32) and -4log(a-1)

viscid thistle
#

which constant

#

C?

mighty onyx
#

yeah

viscid thistle
#

$A+B\log_2(C)$ doesn't this have a similarity with what you just said

obsidian monolithBOT
viscid thistle
#

you just said correctly $\log_2(32)+ -4\log_2(a-1)$

obsidian monolithBOT
mighty onyx
#

yeah but how can we combine them?

viscid thistle
#

${\color{green}{A}}+{\color{blue}{B}}\log_2({\color{red}{C}})$
$\ {\color{green}{\log_2(32)}}+ {\color{blue}{(-4)}}\log_2({\color{red}{a-1}})$

#

wdym by combine?

mighty onyx
#

so C would be a-1

obsidian monolithBOT
viscid thistle
#

yes!

mighty onyx
#

fuck my teacher I had tried that like an hour ago but the page says it's wrong

viscid thistle
#

huh

mighty onyx
viscid thistle
#

bruh

#

you told me it was a-1 not a+1

mighty onyx
#

Albot1288:
@obsidian monolith

viscid thistle
#

oh wait did we really skipped a sign

#

ugh

#

well that's the typo

mighty onyx
#

so a+1 is the correct answer

viscid thistle
#

yep

#

good job

mighty onyx
#

thanks

mighty onyx
#

when doing approximation with.
$\log_b(2)=0.271, \log_b(3)=0.429, and \log_b(5)=0.629.$

obsidian monolithBOT
mighty onyx
#

trying to find $\log_b(25b^3)$ should be using power rule right?

obsidian monolithBOT
viscid thistle
#

not only power rules

mighty onyx
#

I know for $log_b(10)$ you break it down into $\log_b(2*5)$ then into $\log_b(2) + \log_b(5)$

obsidian monolithBOT
mighty onyx
#

when using substitution we get 0.9

#

it's the $b^3$ that's confusing me

obsidian monolithBOT
mighty onyx
#

ooh wait a minute unless we get $25b_3$ by $3\log_b25$ I think

obsidian monolithBOT
novel cargo
#

what is logb(b^3)

viscid thistle
#

For the $\log_b(25b³)=\log_b(25)+\log_b(b³)$ you can use this

obsidian monolithBOT
mighty onyx
#

ok so we would do $(\log_b(5) + \log_b(5)) + \log_b(b^3)$

obsidian monolithBOT
novel cargo
#

you can further simplify if you like

mighty onyx
#

ooh wait log rules $\Log_b(b)^x=x$ right

obsidian monolithBOT
novel cargo
#

you mean logb(b^x) = x

mighty onyx
#

so it would be $0.629 + 0.629 + 3$

obsidian monolithBOT
mighty onyx
#

and yeah

novel cargo
#

would also look better to write 2 * logb(5) + 3

mighty onyx
#

yeah

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Yay look at me learning my log rules

viscid thistle
#

Ok i'm back

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Oh-

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Good job

novel cargo
#

sin(x) + 1 = cos(x)

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domain: [0, 2pi)

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I got, x = 0, x = 3pi/2

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correct?

stuck lark
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@novel cargo KurisuGoodJob

mighty onyx
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$10^{2\log5}$

viscid thistle
#

^{}

obsidian monolithBOT
mighty onyx
#

thx, and how would we evaluate this?

viscid thistle
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is log base 10?

novel cargo
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2log5 = log(5*10)

viscid thistle
#

?

proven marten
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yes

novel cargo
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doesn't help, sorry

proven marten
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10 is base default

mighty onyx
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I'm assuming

viscid thistle
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2log(5)=log(5^2)

proven marten
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if nothing is written its usually 10

viscid thistle
#

Could also be e

mighty onyx
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e is for ln

novel cargo
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I meant 2 log 5 = log(5*2) = log(10) = 1

proven marten
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doesnt 2 log 5 mean log 5^2

novel cargo
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oh, man

viscid thistle
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e is for ln
In higher math log base 10 is so useless that log is usually base e

proven marten
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Kinda confused

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I thought you were in HS

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nvm

viscid thistle
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I am

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But I have my resources

mighty onyx
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I'm in college rip

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but back to the problem, would we need to turn it into $\log5^2$ then get that and raise 10 to the power of what we get?

obsidian monolithBOT
novel cargo
#

this simplifies to 25

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2 log(5) = log(25)

proven marten
#

agree

novel cargo
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which is asking what should we raise 10 to to get 25

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take 10 to that power

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which gives 25

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someone write please the algebra and rules

mighty onyx
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ahhh thanks

novel cargo
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I can't rememebr them

viscid thistle
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How about $\log(30)\approx 1/2$

obsidian monolithBOT
viscid thistle
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$log(25)\approx \log(30)\approx 3/2\approx 1 \approx x \forall x\in \mathbb{N} $

verbal stump
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log30=1+log3>1>1/2

lime bolt
#

do u mean 3/2

viscid thistle
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Yes

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3/2

lime bolt
#

lol that would have been some serious engineering approximations

obsidian monolithBOT
viscid thistle
#

Cursed

lime bolt
#

oh ok

mighty onyx
#

$ \ln\left(\frac{a^2}{b^{-4}c^{-1}}\right)=$ expanded is $\ln(a)^2 - \ln(b)^-4 +\ln(c)^-1$ right?

lime bolt
#

what is that green thing

verbal stump
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$log(25)\approx \log(30)\approx 3/2\approx 2 \approx 3 \approx 4 \approx 10000000000$

obsidian monolithBOT
viscid thistle
#

Oxygen tube

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Anyway log(25) is close to 3/2

obsidian monolithBOT
novel cargo
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ln(a^2) - ln(b^4) - ln(c)

viscid thistle
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Wait base is 10

novel cargo
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taking the powers out of parenthesis means something else

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sorry, ln(a^2) + ln(b^4) + ln(c)

mighty onyx
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wouldn't be ln(c^-1)

viscid thistle
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Which is 2ln(|a|) + 4ln(|4|) + ln(c)

novel cargo
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either -ln(c^-1) or ln(c^1)

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from denominator to nominator power changes sign

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but it becomes a multiplication and not division anymore

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so its subtraction and not addition

mighty onyx
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so if a=2 b=3 and c=5 then we plug them in to find the answer right

novel cargo
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I think that is OK

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but others may know for sure

mighty onyx
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I keep getting ln(1620) is that what yall are getting?

viscid thistle
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Is 1620=2^2x3^4x5?

mighty onyx
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yes

viscid thistle
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Correct

mighty onyx
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so I should be getting 1620? because it says it's wrong

viscid thistle
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No

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ln(1620)

mighty onyx
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but it says it's still wrong

viscid thistle
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No way

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Show question

mighty onyx
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and if I'm right the second one should be 30

proven marten
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Kind of have to ask this

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is this for a test

viscid thistle
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Due in 7 days

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I don't think so

proven marten
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oh

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true

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ig its just an assignment

viscid thistle
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Try evaluating it using a calculator

old nimbus
#

When brining a x up from the bottom of the fraction

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do you add or times it

proven marten
#

Boris