#help-0

1 messages · Page 728 of 1

jade birch
neat kayak
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oh sorry

alpine sable
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alright no worries. so when encountering a rational inequality like this one, you can try looking to solve whenever the num=0 and den=0 (undefined), so that those values of x won't yet be our solution but we'll be our x values where our (x²(x-1)³)/(sqrt(x+7)) will touch the x-axis and hence between those x-values, we'll want to test out some values in those intervals to check whether the (x²(x-1)³)/(sqrt(x+7)) is non-negative (so ≥0) or non-positive (so ≤0), which would be our solution, since it's asking whenever ≤0.

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as this might be a whole new methodology to you, i will recommend watching a video for you to get kind of used to the method for later to get here and try your problems.

merry plank
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oh okay, i'll watch it

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if i still need help w any of them after the fact should i ask?

alpine sable
#

of course. feel free to do so

merry plank
#

ok thanks

tawdry saffron
#

question says:
a bowling ball with radius 10cm rolls in a horizontal V-shaped slot with an opening angle of 60°. The speed of the center of the bowling ball is 18km/h

What is the distance between the centre of the ball and the bottom of the slit

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why do they mention the speed

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of the bownling ball

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or am I just interpreting it wrong

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do you need the speed?

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I think I know a way to solve it but the speed makes me doubt it

vapid oak
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i think the speed is irrelevant

sage jacinth
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lines tangent to a circle are perpendicular to the radius

tawdry saffron
#

okay yea

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I'm on a good path to solve it now, the speed made me overthink

lucid nova
#

can someone help me with this?

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the question is what is the last digit of 2^2017

alpine sable
#

I'll give you the hint that you only need to look at the last digit

lucid nova
#

i know the answer is 4

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but idk how they got that

alpine sable
#

You can see a pattern if you write out the first few terms

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You can probably try the powers of 2

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And see when they repeat

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Basically a pattern

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And divide 2017 by the number of times after which they repeat

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And get the last digit by comparing the index

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2^1 = 2
2^2 = 4
2^3 = 8
2^4 = 16
2^5 = 32

unit digit repeat after every 4 powers you can notice

lucid nova
#

oh thank you very much

hoary fiber
#

people help

glass lichen
hoary fiber
#

k

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thanks

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got it

brisk tree
#

I'm confused between α>=2 and α>2 :/

median gorge
#

Think about what it means for a function to be strictly increasing

brisk tree
#

For all x>y f(x)> f(y).

glass lichen
#

Im assuming this is a calc class?

brisk tree
#

Yes

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We always set f'>0 for strictly

glass lichen
#

so answer Lachlan's prompt in terms of calc

median gorge
#

Alright, cool, however is there another way..

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Yep

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Cool

glass lichen
#

yeah, so you'll have strict inequality

median gorge
#

So now just solve that inequality for alpha

brisk tree
#

so isn't x^2 strictly increasing for all x>=0?

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I'm confused because of the domain of x...

brisk tree
median gorge
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Yes, x^2 is strictly increasing for all x >= 0 however in this case was have x(alpha-x)

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For instance, this is what the function looks like when alpha = 1

brisk tree
#

Alpha=2 seems fine tho

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Don't you think?

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Besides it's (0,1)

brisk tree
median gorge
#

Yeah

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I think I see what you're saying

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Here is what I would do

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I would say that we want f'>0 for all x in the domain

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We know the derivative is alpha-2x

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So alpha-2x>0

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Right

brisk tree
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Yes

median gorge
#

This gives us alpha>2x

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Now we want alpha to be greater than 2x for all x in (0, 1)

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Notice that it doesn't exist at 1

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So if alpha = 2

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That is greater than 2x

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And so I would say that alpha >= 2 is all good

brisk tree
#

Yeah cause 2>2×0.999999

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Okay thanks a lot!!

sage summit
#

I don't think completing the cube counts as witchcraft

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and typically completing the cube is used to reduce from x³+bx²+cx=d to x³+cx=d

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what chapter is this in

warped phoenix
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WHA

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WITCHCRAFT

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WHAT MATH IS THIS, WHAT LEVEL I MEAN 😭

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is this like calculus 3 million

sage summit
#

does it talk about uuh

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covering spaces

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groups

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deck transformations

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if the book is about riemann surfaces what's the chapter about

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ah xD

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lol

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not sure if they intend it to be solvable

pseudo summit
#

How to deal with periodic tithes in the quadratic formula?

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Should I round it?

alpine sable
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Deoends

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Depends*

austere bridge
cinder beacon
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is any1 here smart at math

tranquil parcel
#

Or maybe physics server

ionic jewel
paper oar
#

Jk just ask your question

cinder beacon
#

ill pay someone 25 tom if they can help me in mathe today

paper oar
#

...

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I don't think that is how it works in here...

cinder beacon
#

it might not but i will

ionic jewel
#

have you considered posting your question

alpine sable
#

A square of side 1 contains several circles in its interior. The sum of the circumferences of the circles is equal to 10. If you draw a straight line parallel to a side of the square, how many minimum circles will it always intersect?

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Please help

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Options are: 2,3,4, can't be determined

alpine sable
red phoenix
gleaming snow
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-25x0 do you right it as -0 or +0 if put in an equation

ionic jewel
#

definitely can't be determined with that much information, trivially you could make a circle of circumference 1 and stack 10 of them on top of each other, then depending on where you line is you either go through 0 or go through 10

ionic jewel
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or rather, -0 = 0 and is always written like so

gleaming snow
#

100-25x0+1

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= 100+0+1?

ionic jewel
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yep

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100-0+1 is fine too in this case

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it's the same answer either way

gleaming snow
#

Ok

alpine sable
#

But wasn't getting anywhere

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Since symmetrical orientations didn't work

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Also found out the sum of radii of all the interior circles

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But that isn't getting me anywhere

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I think I found the total number of circles to be in between 9 and 16 but I'm not sure

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<@&286206848099549185>

ionic jewel
#

is there something wrong with my answer?

alpine sable
#

Wait I didn't see

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I'm sorry :(

ionic jewel
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mine seems quite a bit too trivially disprove it, but i don't see a problrm with it

alpine sable
#

Yep

ionic jewel
#

perhaps they mean non-overlapping circles, but i still suspect you can't determine it

red phoenix
#

I believe it requires that it always intersects circles

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But the wording of it all is a bit dodgy

alpine sable
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Yeah

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It's more on the puzzle side ig

warped phoenix
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is this channel free

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gonna assume it is

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how did they get that as the condition probability

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I got $\frac{\frac{79}{98}\cdot \frac{79}{91}}{\frac{79}{91}} = 0.806$

ocean sealBOT
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TheMane3

warped phoenix
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The probability of A, that they have AC, is 79/98, and the probability of C, that they have a companion animal, is 79/91

noble sinew
#

Just read in the C yes coloumn

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79 yes and 12 no

red phoenix
alpine sable
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Tysm for taking the time :)

warped phoenix
noble sinew
#

Because it is conditional?

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Given C=yes

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So look there

warped phoenix
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but 79/91 is the probability they have a companion animal @noble sinew

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since the amount of people with an animal is the same as the amount of people with ac, i get why they use 79 again, but we're not looking for how many people have an animal right

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we're looking for people with ac

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so 79/98 is the probability they'll have an ac right

noble sinew
#

Im saying all you have to do is look here

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Clearly the prob is 79/91

warped phoenix
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79/91 is the probability they have an animal

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right

noble sinew
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It is the conditional prob that the question asks for

warped phoenix
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but its also that right

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79 people have one, 12 people dont, so theres a 79/91 probability that they have one

noble sinew
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No?

warped phoenix
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what

noble sinew
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Both the 79 and 12 are under yes

warped phoenix
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oh 🤦‍♂️

noble sinew
#

But just do what I said

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No reason to do what you are doing

warped phoenix
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what would i do in a future question like this

viscid oriole
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Hello guys, i am re-learning math because i want to get better at it, and there is one thing i don't understand even now about fraction word problems, why for example here must i multiply the fractions to get the right result? Please help me to understand.

glass lichen
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of means multiplication

noble sinew
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Look in the coloumn I marked

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All you have to do

warped phoenix
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ok

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how do i know if a question is conditional

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like what here tells me its a conditional probability

warped phoenix
viscid oriole
# glass lichen *of* means multiplication

i mean i remembered the structure but i still would want to understand more in depth if possible, because at first i thought that i have to divide to get the answer

glass lichen
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*1/4 is the same as dividing by 4, so yes

warped phoenix
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<@&286206848099549185>

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?

glass lichen
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you just determine the independence of the events

warped phoenix
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well thats what i did originall i think, the probability of someone having air conditioning is 120/180, and the probability of someone enjoying opera is 120/720, 120/720 * 120/180 = .1111...

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since 120/720 * 120/180 does equal .1111, it would be independent

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did i do that the right way?

glass lichen
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$P(A\cap B)=\frac{120}{1080}=\frac{1}{9} \ P(A)P(B)=(\frac{720}{1080})(\frac{180}{1080})=\frac{1}{9}$

ocean sealBOT
glass lichen
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so yes they're independent

gaunt magnet
#

anyone good with calc

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that can check my work

warped phoenix
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why do you do the full thing

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like umm

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why the totals

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720/1080 and 180/1080

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howd u know to use those

glass lichen
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cause that's how many people there are

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Probability is desired/total...

gaunt magnet
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no

warped phoenix
#

what

gaunt magnet
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go to ques 1

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i took this channel

warped phoenix
#

dude what

glass lichen
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they were using it before you

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end of story

gaunt magnet
#

no yall didnt talk for 15 mins

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this is mine

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end of the story

glass lichen
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anyways

gaunt magnet
#

nah

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i need help

glass lichen
warped phoenix
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ohhhh

gaunt magnet
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😼

warped phoenix
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and see if i get it right

glass lichen
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yeah

warped phoenix
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ok 1 sec

gaunt magnet
#

Guys?

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check my answer

glass lichen
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No

gaunt magnet
#

who asked u

glass lichen
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You did

warped phoenix
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(actually what would i search to find questions like these? 😅)

gaunt magnet
#

i never pinged u

warped phoenix
glass lichen
gaunt magnet
glass lichen
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they were still using it

gaunt magnet
#

they didnt talk for 15 mins

warped phoenix
glass lichen
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you did every single question in a book?

gaunt magnet
warped phoenix
#

its a chapter of the book

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and there were like 10 questions on it

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its ok

gaunt magnet
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proof

warped phoenix
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i tjink i found one

glass lichen
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stop being an ass

gaunt magnet
gaunt magnet
warped phoenix
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ok so ill make the questionnnnnn...."is the probability of liking snowboards and the probability of liking snowmobiles independent?"

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would that work

robust flax
#

bruh

glass lichen
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sure

warped phoenix
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ok

gaunt magnet
#

im gonna leave but u stole my channel

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@glass lichen F you btw

warped phoenix
#

cool

gaunt magnet
#

bye now

warped phoenix
#

bye bye

gaunt magnet
#

mosh has no life

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for stealing my channel

warped phoenix
#

didnt you say bye just a message ago

glass lichen
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Just ignore them, they're just a troll

gaunt magnet
#

ye il leaving

gaunt magnet
#

this guy is a capper i came for help

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i come here for daily help

glass lichen
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anyway, yeah just determine if those events are indep. like you chose

warped phoenix
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@glass lichen so the probability of liking snowmobiles is 80/125, and the prob. of liking skateboards is 80/105, 80/125 * 80/105 = 0.488, so now we look at the totals like we just did in the last question i think, so 125/160 * 105/160 = 0.512, since 0.488 is not equal to 0.512, they're not independent?

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😓

gaunt magnet
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lol he just ghosted you.

glass lichen
warped phoenix
glass lichen
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you divided by 105 and 125 for some steps

warped phoenix
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oh

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should they all have been out of 160

glass lichen
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yes

warped phoenix
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ahhh ok

glass lichen
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$P(A\cap B)=\frac{80}{160}=0.5$

ocean sealBOT
gaunt magnet
#

ok are u done

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ok

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i take channel now

glass lichen
gaunt magnet
#

no

glass lichen
#

Like is this a really hard concept to understand or are you just being needlessly petty

glass lichen
#

stop being such a dick

gaunt magnet
#

LOL

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🔥

glass lichen
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Like all you've said is "is this right" when any calculator/CAS can answer that for you.

alpine sable
#

why do even need this channel anymore, your question has been answered?

shell heron
gaunt magnet
glass lichen
#

And then you opt to constantly break rules and present yourself as a superior

warped phoenix
#

hmmm what about here

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bruh

gaunt magnet
#

lol

shell heron
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so what

warped phoenix
#

@gaunt magnet we're still doing this?

gaunt magnet
#

okk

shell heron
#

thing is

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im programming in roblox

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and actually testing out games

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but go off

gaunt magnet
warped phoenix
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51/160 chance that they're a senior and working part time

glass lichen
#

yes

warped phoenix
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how would i determine if that bit of info is independent 😅

glass lichen
#

then find probability of each and multiply them

warped phoenix
#

each what

willow wadi
#

we pop at ur party

glass lichen
#

P(senior) and P(working part time)

willow wadi
#

Hello kind people, anyone of u help me in Math

warped phoenix
willow wadi
#

👍

gaunt magnet
willow wadi
#

Ok

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Ill wait

glass lichen
warped phoenix
#

channel in use

alpine sable
#

Oh sorry

warped phoenix
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or was i supposed to do 51/160

glass lichen
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not 51/59

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yes, 51/160

warped phoenix
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80/160 * 51/160 = 0.159

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now what 😅

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51/160 = 0.318

glass lichen
#

compare

warped phoenix
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0.318 isnt 0.159.....soooooo not independent

glass lichen
#

yes

warped phoenix
#

ohhhh

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wait whaaa

glass lichen
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oh they want you to use conditional

warped phoenix
#

the first one is saying 59/160 isnt equal to 51/160, and the second one is saying 80/160 isnt equal to 51/160

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they're both true

glass lichen
#

yeah not sure, but they shouldnt be independent

noble sinew
#

independent if P(A|B)=P(A) so the one you picked is wrong

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so not independent if P(A|B) != P(A)

warped phoenix
#

the first one says 59/160 doesnt equal 51/160

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and the second one says 80/160 doesnt equal to 59/160

noble sinew
#

yes but first one has nothing to do with independence

warped phoenix
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ah because it doesnt follow the formula for independence?

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i see

strong carbon
#

How does the second one do?

warped phoenix
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because it shows P(A) doesnt equal P(B given A)

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which is the formula for independence with a conditional probability

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the first one shows P(B) doesnt equal P(B given A) which doesnt follow the formula

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so while theyre both true, one has something to do with independence and the other is random i believe

strong carbon
#

Ah I see

native cloud
#

Can anyone help me solve this problem?

chilly bobcat
#

help me in the problem pls

gloomy lintel
native cloud
gloomy lintel
#

Yep bc it’s 2 or below

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But the only thing that’s lower than a 2, as an outcome is 1

native cloud
native cloud
wary stream
chilly bobcat
#

yes

wary stream
#

Apply that concept to that problem

chilly bobcat
#

but I don't know how to find it

crude moss
#

please\

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i really need help

native cloud
#

그니까

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반지름 곱하기 파이 2제곱이

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원의 넓이고

wary stream
native cloud
#

반지름 곱하기 2에 곱하기 파이가 원주입니다

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@chilly bobcat

ionic jewel
#

i wonder how well google translate works for translating math words to other languages

Google 번역이 수학 단어를 다른 언어로 번역하는 데 얼마나 잘 작동하는지 궁금합니다.

native cloud
#

I'm Korean

ionic jewel
#

circumference is twice the radius times pi

둘레는 반지름 곱하기 파이의 두 배입니다.

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yeah but im not korean

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im just curious how well it works

native cloud
#

xD

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Pretty okay

winter bay
ionic jewel
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i feel like it might start having trouble if i got too technical though

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not sure

winter bay
#

I think the issue usually occurs when the sentences become complicated

chilly bobcat
winter bay
#

Or colloquial stuff is used

native cloud
#

몰라서 물어본거 아니였어요?

torn raven
#

how do i solve this ? i dk how they got 62%

alpine sable
stray parrot
#

For the perimeter do 2πr

stray parrot
stray parrot
ebon oar
#

anoyne help?

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pls

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'='

glacial hedge
#

Does anyone know how to "solve" this>

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it seems wrong... but maybe im missing someting

placid zinc
#

I don't see any reason to think so

alpine sable
#

I FORGOT ABOUT ALL OF THIS HELP

placid zinc
#

This is basically saying "all 2×2 matricies have non-real eigenvalues"

stray parrot
arctic delta
#

can someone explain why the inequality is important for the limit not existing, if it was = 0 there, an asymptote wouldnt be there?

solar cradle
#

If x approach 3 from the right, the limit goes to positive infinity and if it goes to left it goes to negative infinity

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x - 3 > 0, if and only if, x > 3, so the limit from the right goes to positive infinity. If the limit was approaching 3 from the left it would be negative, because x-3<0

arctic delta
#

what does the 16 > 0 signify?

ebon oar
#

i figured it out anways

solar cradle
#

That 16 > 0? If the limit of the numerator was negative, then the whole limit would approach negative infinity

arctic delta
#

cuz it's done the same way for approaching from the left

solar cradle
#

The limit of just the numerator exists

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so it would be the same

noble sinew
#

If num approached 0 then you had 0/0 expression which you can’t say what value it is just like that

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Hence the important part is num doesn’t approach 0

arctic delta
#

ah, so its saying part of the reason that the func is approaching inf is that the numerator is more than 0?

noble sinew
#

That it isn’t 0

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Because then you can just apply product rule and find limit which is what they did (without saying)

arctic delta
#

in this are they just making the 5 have the same denominator by multiplying the denominator of the left side

slender forge
#

Yes

wicked plover
#

wow

slender forge
slender forge
arctic delta
slender forge
#

It’s all good I did too

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Just make sure u get this stuff down ull use it later down the math line

arctic delta
#

for sure

slender forge
#

What math class/grade is this?

arctic delta
#

its an online intro into calc

slender forge
#

Precalc?

arctic delta
#

yea

slender forge
#

Ya these algebra skills will start to become more important def work on it

arctic delta
#

i'll try

slender forge
#

U can also hmu if u need help with that kinda stuff btw

#

I’m kinda studying math in college rn just a more specialized degree than standard math degree

arctic delta
#

if you're cool with that, thanks, thats a bit reassuring

slender forge
#

Yah np might be a little busier come the end of august when classes come up but for now 🤷‍♂️

arctic delta
#

yea im just trying to get through my course before august ends, gotta get through a mid term, two units, one assignment and a final before then

slender forge
#

College or high school?

arctic delta
#

college ye, its a online one

slender forge
#

Completely online college or just this course?

arctic delta
#

its a completely online one, im planning on transferring the credits from this into my actual uni

slender forge
#

What year/what are you going for?

arctic delta
#

finished my second semester, going for business but i need this credit to try and transfer from law

slender forge
#

That’s cool which business degree or just general business?

arctic delta
#

haven't really put much thought into that so im not too sure

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maybe accounting or finance

slender forge
#

Both not bad choices tbh

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I found accounting kind of boring and liked finance but I have friends who thought opposite

arctic delta
#

hope i dont find whatever i get into too boring

slender forge
#

If u do switch 🤷‍♂️

#

Better to waste some money than rest of ur life

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I just finished my freshman year back in April my sophomore year starts end of august btw

arctic delta
#

nice, just stressful to think about but true

glass flare
#

how do i create a right left arrow in latex

austere bridge
#

$\rightarrow$?

ocean sealBOT
#

cgodfrey

austere bridge
#

oh

#

$\leftrightarrow$

glass flare
#

??

ocean sealBOT
#

cgodfrey

austere bridge
#

there we go

glass flare
#

oh lol

austere bridge
#

or $\longleftrightarrow$

ocean sealBOT
#

cgodfrey

glass lichen
#

$\iff$

ocean sealBOT
glass flare
#

$\longlongleftrightarrow$

austere bridge
#

$\Longleftrightarrow$

ocean sealBOT
#

cgodfrey

#

JeffTheRef
Compile Error! Click the errors reaction for more information.
(You may edit your message to recompile.)

glass flare
#

$69x^4+420x^3+69x^2+420x=69$

ocean sealBOT
#

JeffTheRef

glass flare
#

$e^{\pi i}+1=0$

ocean sealBOT
#

JeffTheRef

glass flare
#

$ x{\leftrightarrow}x$ and $\iff$ and $ x{\longleftrightarrow}$

ocean sealBOT
#

JeffTheRef

solar cradle
#

There's a latex help channel and testing channels

glass flare
#

ohh sorry

clever mountain
#

So i'm not very good at math but i was wondering how to use this function to squish a number between 0 and 1, i'm trying to figure out what to set x and e to.

clever mountain
glass lichen
#

like 2.71828... irrational garbage

#

$e=\lim_{n\to\infty}\left(1+\frac{1}{n}\right)^n$

ocean sealBOT
clever mountain
glass lichen
#

I mean you could've guessed from the function notation it was the number e

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since S was only a function of x

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But yes, $S:\mathbb{R}\to (0,1)$

ocean sealBOT
severe robin
willow wadi
sage jacinth
sterile crescent
#

If z= a-ib, then mod z will still be, root(a^2+b^2)?

remote lodge
#

going to sound stupid here but..

#

how is the 4/6 simplified?

vapid oak
#

$\frac{4}{6}=\frac{22}{23}=\frac{2}{3}$

ocean sealBOT
#

Omfish

remote lodge
#

Ok thanks Omfish 😅

carmine lion
#

how to do part (a) and (b)

#

for part a

#

i solved $P'(x)=0$ and got $x=0, -\frac{2B}{3A}$

ocean sealBOT
carmine lion
#

but how do i rule out x=0 as a solution

#

what reason should i state

#

also for part b, should the 2nd term on the LHS be -4B^3?

#

because i get 8B^3=0 when i simplify part B

#

and the quesiton stated B cannot be 0

wild marten
carmine lion
#

yea

#

ok

#

now part b

flint willow
# carmine lion now part b

Hey, um idk if you have already solved it yet. But if not, just substitute the value of X you got from the part a (That is -2B/3A) in the original equation.

#

That is it

carmine lion
#

and i get 8B^3=0

#

which means B=0

#

but B cannot be 0

#

as the question had imposed ccertain restrictions earlier

#

soooo

#

idk whats going on

wild marten
#

see, if you substitute $\frac{-2B}{3A}$ in the original equation, you get:
$$A\cdot \frac{-8B^3}{27A^3} + B\cdot \frac{4B^2}{9A^2} + D$$
$$= \frac{-8B^3}{27A^2} + \frac{4B^3}{9A^2} + D$$
$$= \frac{-8B^3+12B^3}{27A^2} + D$$
$$= \frac{4B^3}{27A^2} + D$$
$$= \frac{4B^3+27A^2 D}{27A^2}$$
But since our equation equals $0$, we get that:
$$4B^3 + 27A^2 D = 0$$
Hence, proved

ocean sealBOT
#

Schrödinger's Smile

wild marten
carmine lion
#

oh wait nvm

#

sorry

wild marten
carmine lion
#

nothing

#

i made a silly mistake

wild marten
#

ohk np

carmine lion
#

yehh

covert agate
#

hi

alpine sable
#

bruh

#

this isnt a grammar server

covert agate
#

does the logical statement “either a or b” mean “a xor b”

alpine sable
#

but yeah youd be wrong. because its either, not both

#

meaning only one is true

alpine sable
#

yes

covert agate
#

lol brilliant is wrong

placid zinc
#

@covert agate
XOR is a precise mathematical function
"either a or b" is imprecise.

#

Sometimes they're the same, sometimes not.

covert agate
#

huh

vale wigeon
#

"either a or b" does not unambiguously mean "but not both"

covert agate
#

statement: “either you or me is math major”
reality: both math majors
conclusion: statement false?

dry berry
#

can someone help?

willow wadi
vale wigeon
#

why are you pinging helpers on gansta's behalf thonk

willow wadi
#

so i help him

#

and ping for him

dry berry
#

well im back

#

i got the solution but i don't really understand it

willow wadi
#

@vale wigeon helper he no understand

dry berry
#

so here it is

vale wigeon
#

ah yes

#

do the words 'asymptotic equivalence' ring any bells to you?

dry berry
#

never heard 😛

vale wigeon
#

that's what the tilde means that you circled

#

essentially, we say $f(x) \sim g(x)$ if $\lim \frac{f(x)}{g(x)} = 1$ (as $x$ approaches whatever we need it to approach)

ocean sealBOT
vale wigeon
#

asymptotic equivalence means, roughly, that one function can be replaced with another in a product

#

this can be accomplished without explicitly mentioning it by multiplying your fraction by x^2/x^2 and grouping the x^2/tan^2(x) together (and acknowledging it approaches 1)

dry berry
#

ok...

#

but if so can we substitute tanx = x on the numerator so that the limit equals 0?

vale wigeon
#

no

#

one function can be replaced with another in a product

#

this means that if f ~ g then we have lim h*f = lim h*g

#

asymptotic equivalence is also preserved if raising both functions to a constant power, which covers doing this in the denom of a fraction

dry berry
#

so it is product only...

#

thanks @vale wigeon

#

i think i get it

#

although i just read the definition 😛

golden falcon
# dry berry so it is product only...

technically you can use equivalences in sums, but you'd have to prove that you don't miss anything behind that o(x), or whatever you'd be left with, when you do that. With multiplication it's guaranteed(can be proven in general) that you'd be fine.

golden falcon
#

that's not how it works. You first post a question, then ask for help.

#

Use subtraction

woeful pulsar
#

just apply the subtraction algortithm

#

you can do it with small numbers, you can do it to large numbers

#

can you do it if the numbers are smaller?

#

then can you follow the same steps to subtract?

golden falcon
#

You will get banned or muted if you act uncivilised

woeful pulsar
#

if you want you can show your rough work as you go along

golden falcon
#

here you go

#

cool

woeful pulsar
#

sounds quite inappropriate

golden falcon
#

now try doing that, but instead of milk use numbers you were given and instead of pouring it out, subtract them

woeful pulsar
#

it says don't click it

#

trivially we don't click it

alpine sable
woeful pulsar
#

also aren't you asking for help on subtraction

vale wigeon
#

kaden, what are you doing?

golden falcon
#

He's struggling with subtracting

vale wigeon
#

what is all this about?

woeful pulsar
#

or just trolling

vale wigeon
#

asters?

woeful pulsar
#

asters?

vale wigeon
#

what's an asater?

woeful pulsar
#

sounds like troll

ionic jewel
#

^

woeful pulsar
#

okay probably troll

vale wigeon
#

okay you are definitely a troll

#

<@&268886789983436800>

#

that is an obscene gif that you definitely did not need to post either

tall wing
#

gross

golden falcon
#

what first grade subtraction exercise does to mf

tall wing
#

banned

lament rock
#

can anyone explain how they got 1/k(k+1) = a/k - b/k+1

indigo jetty
#

partial fractions

manic glade
#

can i get some help understanding what this means

vale wigeon
#

f is a function from A to B

#

g is a function from the powerset of B to the powerset of A which sends each D ⊆ B to its preimage by f

analog fable
#

Hello I was doing a worksheet and this question popped up, can anyone help me?

jagged imp
#

do you know about eulers formula for polyhedrons

#

v-e+f=2 for any polyhedron

#

v being the number of vertices, e the number of edges and f the number of faces

ionic jewel
#

another Euler's formula? didn't even know about that one

wind bane
quaint python
#

? <@&286206848099549185>

lusty plaza
# quaint python ? <@&286206848099549185>

I don’t know the answer but I will say that the helpers in this discord tend to help people more when there’s a demonstration at an attempt at solving a problem when posting

mild tartan
#

help, ping me when u get solution, thanks

jagged imp
#

,rotate

ocean sealBOT
jagged imp
#

I simply will not

mild tartan
#

im quite stupid

#

@jagged imp help me!

jagged imp
#

the question is missing information

mild tartan
#

oh

#

nvm im retarded

#

its c)

#

i thought it was a question itself

#

was tryna help my friend find ans

short spear
#

𝑎 is directly proportional to the square of 𝑏 and inversely proportional to 𝑐. Find the effect of 𝑎 when 𝑏 is increased by 10% and 𝑐 is increased by 20%

#

imma need some help

#

with this question

wind bane
#

have you tried anything at all?

alpine sable
#

𝑎

alpine sable
#

a𝑎

short spear
#

i copy pasted

alpine sable
#

interesting

#

wat

wind bane
#

please ask in another channel

short spear
alpine sable
#

channel is occupied

wind bane
#

all of them are open but this one atm lol

#

we dont help with exams here

#

you will straight up be banned from the server if you ask for help on an exam

wind bane
#

okay...

short spear
#

this is the explanation

#

and i don't know how they did this

#

from the first one to the second

short spear
wind bane
#

what happens to a when you increase b by ten percent

mild tartan
#

oh

wind bane
#

so multiplying b by 1.1 has the effect of increasing b by ten percent. same with multiplying c by 1.2; it has the effect of increasing c by 20 percent

mild tartan
#

i think i got it

wind bane
#

k is just some proportionality constant

short spear
#

yeah

mild tartan
#

the increased/decrease of a will be in %?

short spear
#

yeah

wind bane
#

and after carrying out some computations, the effect of increasing b by 10 percent and c by 20 percent has the effect of scaling a by a ratio of 1.21/1.44

#

there are some typos in the solution, mainly just that they forgot to write b^2 in a couple places

short spear
wind bane
#

a_new is given by k(1.1 b)^2/(1.2 c) which is in turn equal to (1.21/1.2) kb^2/c

#

is that what you were asking

short spear
#

yeah

#

ohhhh

#

right i figured it out

wind bane
#

cool

short spear
#

wait quick question

#

how did they square 1.2

wind bane
#

they shouldnt have because thats wrong. good catch

#

this "solution" is riddled with errors

short spear
#

yeah the marker must've been in a rush

#

ah well thanks anyways

forest garden
#

Guys is there a formula to finding a general sequence from a recursive sequence? Like for example how do we get from a[1] = 1; a[n] = a[n-1] + n to a[n] = (n(n+1))/2 ?

vale wigeon
#

no

#

there is no formula in general

#

it can be very hard if the recurrence relation is nasty enough

forest garden
#

Ah I see. So the only way is just to like... get something by the slope of the sequence or something?

ionic jewel
#

there are a lot of techniques for solving recurrence equations

#

i took a class that almost exclusively focused on solving them

forest garden
#

I see. So there are actual ways other than just trial and error?

ionic jewel
#

the real moral of the story is that you can just plug it into wolfram and not learn how it works

forest garden
#

Hm right

ionic jewel
forest garden
#

Yea it's okay

ionic jewel
#

it's kinda like differential equations, different types need different solutions

#

not all of them are easy

vale wigeon
#

if your recurrence relation has a certain form there are techniques which let you solve it

ionic jewel
#

^

forest garden
#

Right

#

But

ionic jewel
#

master theorem go brrr

forest garden
#

I appreciate it, the info I mean

#

Thanks

ionic jewel
forest garden
#

Oooo

ionic jewel
#

this is a way to solve some subset of them

forest garden
#

Using Big O?

#

I never thought something like that can help lol

ionic jewel
#

this isn't quite what i was thinking it was, but there's something in here that gives you the exact forms

forest garden
#

I see

#

Thanks!

graceful river
#

y=x makes 45 dgree angle with the positive direction of x-axis

#

right?

rigid smelt
#

yes

graceful river
#

so how do i do b

rigid smelt
#

,rotate

ocean sealBOT
rigid smelt
#

can you post the other pic again?

graceful river
rigid smelt
#

im wearing a neck brace rn from all of the other vertical pics

#

,rotate

ocean sealBOT
graceful river
#

that img is just for thq context of the question

#

ignore a

rigid smelt
#

if a line makes a 45 degree with the positive x-axis then the slope of the line is tan(45) or 1

graceful river
#

yeah

#

which is y=x

#

oh

#

it sais coordinateS

#

so all i have to do is x=x^3-x^2

#

and get all x coordinates

rigid smelt
#

no y=x is just one of the line that has slope 1

graceful river
#

oh

#

nvm then

rigid smelt
#

there are infinitely many lines with slope 1

#

all of those make a 45 degree angle with the positive x-axis

graceful river
#

so what do i di

#

do

rigid smelt
#

you have the general equation of the tangent

#

and you also have the slope

#

which is also?

#

(not talking about 1)

graceful river
#

huh?

rigid smelt
#

the slope of the tangent is what?

#

how do you find the slope of the tangent line to a curve at some point (a,b)

graceful river
#

rise over run

rigid smelt
#

ehh no

graceful river
#

or y2-y1/x2-x1

rigid smelt
#

thats the slope of the secant line

#

lemme ask you, how did you find the coordinates in question a?

graceful river
#

well

#

if u differentiate it

#

u get f'(x)

rigid smelt
#

yep

graceful river
#

u put f'(x)=0

rigid smelt
#

why?

graceful river
#

which then is parallel to x-axis

rigid smelt
#

why do you know f'(x)=0 gives you the coords where the tangent line is parallel to the x-axis?

graceful river
#

bc that tangent line has to be a horizontal line

#

when dy/dx=0

rigid smelt
#

not the answer im looking for, but yes

#

the derivative at that point is the slope of that tangent line

graceful river
#

yes

rigid smelt
#

what is the slope of the tangent line in part b?

graceful river
#

OH I GOT IT

#

since m=tanx

#

1=tank45

#

the gradient of the tagent line must be 1

#

so therefore

#

1=dy/dx

rigid smelt
#

yes

graceful river
#

since the domain is bigger than 0

#

x=1

#

y=0

rigid smelt
#

yes

graceful river
#

ughhhh it was this ez all along

#

how was i this stupid

#

thx bro

clear apex
#

BRUHHH

#

IM CRYING INSIDE

#

IDK HOW TO DO THIS QUESTION

#

somebody help me on how to do this

vale wigeon
#

have you made any progress or are you stuck not knowing how to begin?

clear apex
#

i kinda did

#

gimme a sec

#

i send ss

vale wigeon
#

please do

clear apex
#

i went up to this

#

but like where do i go next

vale wigeon
#

aha

#

alright, this is in line with what i was going to suggest

#

so you see that the two segments in the lower left are equal to each other, yes?

clear apex
#

can u highlight

#

or can i call u and stream it?

vale wigeon
#

one moment

#

i will highlight it

clear apex
#

kl

vale wigeon
clear apex
#

yh those

vale wigeon
#

these are what i'm talking about

#

they are equal

clear apex
#

ik

vale wigeon
#

let's call them both z, as i did on the pic

clear apex
#

ok

vale wigeon
#

then we have that (x+z)^2 + (y+z)^2 = (x+y)^2, don't we?

clear apex
#

yh

#

i did that originally and got nowhere

vale wigeon
#

what do you get when expanding this?

clear apex
#

ok

#

u get

#

x^2 + 2zx + z^2 + y^2 + 2zy + z^2 = x^2 + 2xy + y^2

vale wigeon
#

2z^2 + 2(x+y)z + x^2 + y^2 = x^2 + y^2 + 2xy

#

indeed

#

we can simplify this to z^2 + (x+y)z - xy = 0

clear apex
#

wait what

vale wigeon
#

subtract x^2+y^2 off both sides

#

then divide by two

clear apex
#

oh

vale wigeon
#

or are you asking how to get from your thing to mine?

clear apex
#

yh

#

acc nvm

#

can u continue pls

vale wigeon
#

the area is equal to (x+z)(y+z)/2

#

which should be clear if you look at the diagram

clear apex
#

ok

vale wigeon
#

(x+z)(y+z) = z^2 + (x+y)z + xy

#

= (z^2 + (x+y)z - xy) + 2xy

#

does this make sense to you?

clear apex
#

yh kinda

vale wigeon
#

well from this we see directly that (x+z)(y+z) = 2xy

clear apex
#

OH

#

ok

#

pls continue

vale wigeon
#

we're one step away

clear apex
#

bruh

#

i get it

#

2xy / 2 = xy

vale wigeon
#

exactly!

clear apex
#

THX SO MUCH

vale wigeon
#

a little clever algebra goes a long way

clear apex
#

lol

vale wigeon
#

i'm serious

sleek elbow
#

sounded funny I guess

vale wigeon
#

it's true though. a lot of problems crack open when all you do is algebraic cleanup without being afraid of what the end result may be

sleek elbow
#

yeah true

clear apex
#

are u guys from uk?

alpine sable
#

A cubic equation $x^3 -5x^2 + 17x - k = 0$ has a root $\alpha$ at $x = 2 - 3i$ \\
a) Find the other complex root and the real root \
b) Hence find the value of k

ocean sealBOT
#

ZED_118

vale wigeon
#

@alpine sable have you made any progress thus far?

sleek elbow
clear apex
#

us?

sleek elbow
vale wigeon
#

russia

clear apex
#

bruh u guys are smart

sleek elbow
#

Ann is, im not lol

clear apex
#

u guys do alevel?

alpine sable
vale wigeon
#

how did you find k to be 13?

sleek elbow
vale wigeon
#

ah wait, i think i know how you did it

alpine sable
#

plugging 2-3i into the x

vale wigeon
#

you plugged in alpha

#

okay yeah

#

well

#

the conjugate of 2-3i will be a root as well, bc the coefficients are all real

#

for the third root you can either get the sum of the roots from the x^2 coefficient, or the product from the constant term

alpine sable
#

2 + 3i?

vale wigeon
#

yup

vale wigeon
#

vieta's formulas

fair crater
#

If that's not within reach maybe comparison of coefficients would work, but I didn't try this out yet

vale wigeon
#

alternatively, just expand $(x-a)(x-b)(x-c)$ and observe that you get $x^3 - (a+b+c)x^2 + (ab+bc+ca)x - abc$

ocean sealBOT
fair crater
#

^

alpine sable
#

but where did you get (x-a)(x-b(x-c) from?

vale wigeon
#

i was trying to explain why the "read sum & product off coefficients" trick works

alpine sable
#

yeah i understood that

vale wigeon
#

so i told you to expand a generic cubic in factored form with a, b, c as its roots

alpine sable
#

how do you know that (x-a)(x-b)(x-c) is a generic cubic?

vale wigeon
#

...

#

are you asking me why i named the roots a, b and c instead of something else? or what

alpine sable
#

no

vale wigeon
#

the roots are what i wanted to give names to here

alpine sable
#

im asking how is (x-a)(x-b)(x-c) a generic cubic

#

how did you generalise that

vale wigeon
#

every cubic can be factored completely over the complex numbers

#

i mean, ok, i'm also setting the leading coefficient to 1, simply to get it out of the way

alpine sable
fair crater
alpine sable
fair crater
#

No, I assume from your question that

#

You potentially see a cubic polynomial not of the form (x-a)(x-b)(x-c)?

alpine sable
#

No, I just want to understand how you get to that form

fair crater
#

Right so basically an assumption is that a cubic polynomial can have up to 3 roots

#

These polynomials are factored into the form (x-a)(x-b)(x-c) where a,b,c are the roots

#

[Anyway I wrote here assumption, but it can be proven]

alpine sable
#

how would you prove it?

fair crater
#

I wouldn't prove it, but someone smarter than me did prove it

#

But anyway if you can accept it has 3 roots

#

Then you should be able to accept the 'decomposition' of ax^3+bx^2+cx+dx^0=(x-q)(x-w)(x-r)

#

For any (a,b,c,d) to corresponding (q,w,r)

alpine sable
#

So basically, you're assuming that $ax^3 + bx^2 + cx + d = 0$ with roots $\alpha$, $\beta$ and $\gamma$ can be factored into $(x - \alpha)(x - \beta)(x - \gamma)$ which in turn gives you $x^3 - (\alpha+\beta+\gamma)x^2 + (\alpha\beta+\beta\gamma+\alpha\gamma)x -\alpha\beta\gamma$ \\
however, wouldnt you have to first divide the first equation by a? \
$\frac{ax^3}{a} + \frac{bx^2}{a} + \frac{cx}{a} + \frac{d}{a} = 0$ Meaning that in the last equation, $\alpha+\beta+\gamma$ is actually divided by a??

fair crater
#

Oh, right, that's definitely a miss on me

ocean sealBOT
#

ZED_118

fair crater
#

Right, since I messed up, it's x^3+bx^2+cx+d=(x-q)(x-w)(x-r)

#

a can't fit into the previous cubic polynomial form since it would need to be multiplied with the x-es

#

The previous form would require a=1 basically

alpine sable
#

Alright, I think i get it anyways. But Im still curious as to how you prove (x-a)(x-b)(x-c)

#

@vale wigeon

vale wigeon
#

"prove (x-a)(x-b)(x-c)"?

fair crater
#

There are 2 parts to that statement: the existence of 3 roots, and that you can factor polynomials out that way

alpine sable
vapid oak
#

that user must be in light mode ig

vale wigeon
#

how dare you slander me so

alpine sable
ocean sealBOT
#

ZED_118

vale wigeon
#

you're essentially asking me to prove FTA for cubic polynomials

#

dont feel like doing that rn

vapid oak
#

maybe research Vieta's Formula

vale wigeon
#

@vapid oak no, it's a config option. ,tex --color light

vale wigeon
#

fundamental theorem of algebra

alpine sable
#

ah

#

you would have to prove that

#

?

fair crater
#

Yes

#

The factor theorem needs to be separately proved too

#

It's the 2 parts I mentioned

alpine sable
#

So I should either try understanding how the fundamental theorem of agebra is proven, or I can simply go on with life just assuming that I can do (x-a)(x-b)(x-c)

fair crater
#

From what I see, you could probably do it in university math year 1/2?

#

But before that I don't know how you would get the requisite knowledge (assuming standard curricula)

alpine sable
#

so

#

going back to the initial question

#

I use (sum of the roots) = 5?

#

2+3i + 2 - 3i + c = 5

#

this?

#

hence the real root is 1?

warped phoenix
#

for dependence of a conditional Probability, P(A|B) should not equal P(A), in the example my teacher is doing, she says it's dependent because P(N|B) isnt equal to P(B), how does this make sense? In order for it to be dependent, shouldn't P(N|B) not equal P(N)?? Why does she compare it to P(B)

fair crater
warped phoenix
#

anyone?

#

<@&286206848099549185>

glass lichen
halcyon geode
#

Hard to read whatever is there tbh

warped phoenix
glass lichen
#

if you mean why she wrote about P(B) and P(N|B)... that's cause those are the givens...

warped phoenix
#

@glass lichen No she wrote it weird but when she talks she said "Because P(B) and P(N|B) are not equal, it is dependent"

#

thats what im confused about

glass lichen
#

so ask her...

#

probably just a misspeak

warped phoenix
#

she wont respond until monday

glass lichen
#

so wait

warped phoenix
#

i need to get this done today, regardless, how are we supposed to know if it dependent or not, we'd find P(N), right?

glass lichen
#

idk why 1 thing is gonna nullify everything else you've been taught in class / this discord, so dont make a big deal out of it

#

yes you need P(N)

warped phoenix
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ok

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ill be home in a couple hours and try again

velvet condor
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easy question

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let x^6-3x^2y^4=69
and y^6-3x^4y^2=6969
calculate x^4+y^4

vapid oak
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can i rewrite in latex to see if i understand right cuz its a bit confusing

velvet condor
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sure,

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btw how do i use align thingy:)))

vapid oak
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$x^6-3x^2\cdot{y^4}=69 \ y^6-3x^4\cdot{y^2}=6969. \ Calculate {x^4+y^4}$

velvet condor
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i think u may need ~

glass lichen
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$x^6-3x^3y^4=69 \ y^6-3x^4y^2=6969$ Calculate $x^4+y^4$

ocean sealBOT
drifting basin
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That was hurting my head trying to read that haha

ocean sealBOT
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Omfish

vapid oak
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whatever sorry im wasting time

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hey i just graphed the two equations, it looks like there arent any solutions for x and y

velvet condor
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doesnt matter:))

drifting basin
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Did you graph the first one as x^6 - 3x^2 * y^4

vapid oak
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yep