#precalculus

1 messages · Page 139 of 1

mystic rune
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now go and practise

deft flume
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thanks for the wise words

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i will do my best^^

south rivet
valid vector
royal gull
#

,rotate

obsidian monolithBOT
valid vector
#

Can someone help me solve for the variable in these four exercises?

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I'm confused as to how to do it.

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I've got all the log properties, but I'm still confused.

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Please tag me

forest geode
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log(3z) = 2 => 3z = 10^2

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3z=100, z= 33.333..3

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@valid vector

valid vector
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Yeah, I managed to do that one. The others I'm still missing, though. Thanks, tho!

forest geode
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The other ones are the same

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instead of 3z write sqrt(x-8)

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so sqrt(x-8) = 10^5

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just a huge silly number

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x = 10^10 - 8

viscid thistle
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i hate math

kind pier
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I need help factoring something simple

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(1/x) - 1 / x-1

fringe stream
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is it supposed to be $\frac1{x} - \frac1{x - 1}$?

obsidian monolithBOT
slow wharf
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What's the differebce between lo g division and synthetic division?

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They achieve the same thing as far as I know.

dull tartan
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The method of solving

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Synthetic division can be used to factor and solve polynomials

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Watch a video on long division and synthetic division. So long as there are no fractions, synthetic can be very clean and easy

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Synthetic substitution can also be used with the rational zero theroem

short sorrel
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Synthetic division is really just a special case application of long division

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For specific polynomials

dull tartan
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Yes

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The divisor has to be (x - p)

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For synthetic

short sorrel
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Like how the long division you learn in elementary school is really just polynomial long division where your variable is an implied 10 instead

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Ie long dividing 475 is like long dividing 4(10^2) + 7(10) + 5

dull tartan
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@slow wharf

slow wharf
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Yes

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Oh, I see

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Because synthetic division seems simpler

dull tartan
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And is multipurpose

slow wharf
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Multipurpose?

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I'd use it for like integrals

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If you know what I mean

dull tartan
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Sometimes you'll get a polynomial with the factor x+2

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If that polynomial is x^2 + 4x + 4

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And they say to factor

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-2 | 1 4 4

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(Im on mobile, sorry)

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( x + 2 ) ( x +2 ) is that factored

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If the remainder is zero, it is a factor of the polynomial

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This can ve done with more complicated polynomials

slow wharf
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Can the same thing be achieved with both syntheti division and long division

dull tartan
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Tbh I'm not sure

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But synthetic is def the way to go if permissible

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Mayne @short sorrel can shed some light

short sorrel
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Basically yeah, synthetic division is used when it works (division by x-a) mostly because of convenience

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Can't think of any cases where synthetic division is effective where long division wouldn't be

timber forum
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Anyone here know what is the limit+inf of 1^x

patent beacon
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1

final rover
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Isn't 1^x an undetermined form ?

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Since $1^x=e^{x ln(1)}$

obsidian monolithBOT
fading token
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And ln(1) = 0... What's your point?

mild warren
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1^x is only indeterminate in an infinite limit

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1^x for any real given value should just be one

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So it's just 1=1 lol

final rover
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But... he was talking in an infinite limit.

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And "0*infinity" is an undetermined form.

barren hedge
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Eh, that ln(1) is a constant 0, so a bit different. You can think of it as 0+0+⋯(∞ times) in this case. Now if it wasn't a constant 0 (like 1/x as x→∞) you would need to show more work (like in the indeterminate case of x·1/x).

thick raptor
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Analogy:
0/0 is indeterminate, but lim{x->0} 0/x is very clearly 0.
Similarly, 1^infinity is indeterminate, but lim{x->infinity} 1^x is very clearly 1.

spring thunder
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@final rover so that you may see the answers one day

final rover
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I think I took the problem when the 1 was from something that converges to 1... That's why I couldn't understand... Well, I think. But if the 1 is constant, then yes, 1^x when x goes to the infinity is 1.

patent beacon
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The "very large real number" analogy works for me. It only fails at something like (1 + 1/x)ˣ

final rover
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That's what I was thinking

winged lava
willow bear
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what's the question?

rigid beacon
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^

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also it should be r^2 on the left hand side

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since it's x^2 and y^2

willow bear
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yes

winged lava
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Change the rectangular equation into a polar equation

rigid beacon
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oh

willow bear
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well you just did that then, did you not?

winged lava
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Thats only if its x^2 + y^2 right?

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i have to isolate R

rigid beacon
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oh fuck that lol

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oh

willow bear
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divide out by r

rigid beacon
#

well r^2

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on the left side

willow bear
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to get $r(\cos^2(\theta) - \sin^2(\theta)) = \cos(\theta)$

obsidian monolithBOT
rigid beacon
#

(it should be r^2?)

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nvm

willow bear
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i divided both sides by r

rigid beacon
#

you divided on the right

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yea

winged lava
#

o

willow bear
#

this can, if you want, be rewritten as $r \cos(2\theta) = \cos(\theta)$

obsidian monolithBOT
winged lava
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we didnt learn that identity 💦

rigid beacon
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wot

willow bear
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did you not? fair enough, that's optional then

rigid beacon
#

you never learned cos(a+b) and sin(a+b)?

winged lava
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wel we did

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That one ^

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But not the r one

idle dust
rigid beacon
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it's the same thing

winged lava
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uwot

rigid beacon
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yea

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it's still sin and cos

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just cause you're in polar doesn't mean trig is different

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sin is sin, cos is cos

willow bear
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But not the r one
??

idle dust
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yeah i cant find the 2r one either

winged lava
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hold on lemme process this rq xdd

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oh i see

rigid beacon
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oh

winged lava
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you factored out r first

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derp

rigid beacon
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oh yea

idle dust
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nani

winged lava
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but then how would I isolate it on one side

idle dust
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im beyond confused

winged lava
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i think r is just 0

willow bear
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@viscid thistle no spam.

rigid beacon
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@winged lava lemme write out the work 1 sec

winged lava
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👌

rigid beacon
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you see what I did?

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@winged lava

winged lava
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uh hold on my data is kinda slow

rigid beacon
#

oof

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is aight

winged lava
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wait

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omg

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im a fool

rigid beacon
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that happens to all of us lol

winged lava
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It really was r^2 oof

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Tyty

rigid beacon
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(i been saying t hat from the beginning but ok)

winged lava
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no I thought you meant like

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x^2-y^2=r^2 xdd

rigid beacon
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oh lmao

ruby otter
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some one help me with wavy curves

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how do i draw wavy curves for functions having mod function in it

serene heath
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post a question

ruby otter
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ya im finding difficulties to tex it

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thats why its taking time

spring thunder
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tex is usually harder than drawing things tbh

serene heath
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there should be a || thing on your keyboard

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bottom left

ruby otter
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tex it
(2|x| -2) / ( x^2 -2x )

serene heath
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that looks rough thonkeyes

ruby otter
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tex that i have got the rest

spring thunder
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$\frac{2|x|-2}{x^2-2x}$ so this

obsidian monolithBOT
spring thunder
#

?

serene heath
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best thing with thses

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is to look at 2 different cases

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when x>0

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and when x<0

ruby otter
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f(x) = ({x}^{2} - 2|x|)(2|x|-2)-9 ($\frac{2|x|-2}{x^2-2x}$)

obsidian monolithBOT
serene heath
ruby otter
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-_-

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f(x) = $({x}^{2} - 2|x|)(2|x|-2)-9 ($\frac{2|x|-2}{x^2-2x}$)$

obsidian monolithBOT
spring thunder
#

$f(x) = ({x}^{2} - 2|x|)(2|x|-2)-9 (\frac{2|x|-2}{x^2-2x})$

obsidian monolithBOT
spring thunder
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englobe every math smh

ruby otter
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thanx bruh

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how do i put wavy curve for it

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wait

obsidian monolithBOT
ruby otter
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this is the correct question

rigid beacon
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what are you trying to do?

ruby otter
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wavy curve this

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indeed my doubt is big

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but if i had to explain it will take years to tex it

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so better u can say the answer i will clarify my doubt

spring thunder
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so you wanna graph this ? oof

rigid beacon
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plug and chug lol

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this shit is dumb

ruby otter
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not graph

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just wavy curve

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its easy

rigid beacon
spring thunder
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wym?

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the variations of the curve?

ruby otter
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wait first u know what is wavy curve right??

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or u know it by some other term??

spring thunder
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explain wavy curve then ig

ruby otter
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Wavy curve

  • number line rule
  • sign scheme for rational functions
spring thunder
#

ahh

ruby otter
#

these are alternatives names

spring thunder
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so you just wanna find the sign of the function ?

ruby otter
#

exactly

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where it is +ve where it is -ve and zero

ruby otter
#

dont the simplifications

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i give the terms wait

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(2|x|-2) [ ( |x| -1 ) ^2 +2 ] [ ( |x| +1 ) ( |x| -3 ]

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numerator

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x^2 -2|x| is Dr.

obsidian monolithBOT
ruby otter
#

$f(x) =(\frac{(2|x|-2) [ ( |x| -1 ) ^2 +2 ] [ ( |x| +1 ) ( |x| -3) ]}{x^2 -2|x|})$

spring thunder
#

ok yeah seems gud

obsidian monolithBOT
ruby otter
#

my only prob is denominator

spring thunder
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yeah there's a little trick you can use

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the fact that |x|² = x²

ruby otter
#

-__-

rigid beacon
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it's true tho

ruby otter
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even then i cant handle |x|

spring thunder
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x^2 - 2|x| = |x| (|x|-2)

ruby otter
#

i did it though

spring thunder
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it's positive iff |x|>0 and |x|-2>0 (you can't have |x| < 0, so you don't have to consider the case when the two factors are negative)

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ie when |x|>2

ruby otter
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no bruh

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what are you doing

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it is supposed to be |x| , |x| -2 =0 not >

spring thunder
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it's even easier then

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you get |x| = 0 or |x|-2 = 0

ruby otter
#

ya i thought the same but while plotting the signs in the graph i made the mistake

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can u just try it once pls

spring thunder
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try what once ?

ruby otter
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sign scheme

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solve the question

spring thunder
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and if you're just doing +,-,+,- for the signs of x^2 - 2|x|, one advice : never trust absolute value

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that's why i'm just solving the inequation manually 😎

ruby otter
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ya do it'

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i will wait

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the graph comes to be symmetric

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the graph of mod is always symmetric

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but when i graph it
it is not symmetric

spring thunder
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when i graph on wolfram it is symmetric

ruby otter
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ya i know that

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what did u get??

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do u get smtng symmetric ?

spring thunder
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for the signs also ye

ruby otter
#

pic?

spring thunder
#

dem my phones out of battery

ruby otter
#

.........

spring thunder
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is ok just lemme charge it 2min

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dem i didn't think it was so blurry

ruby otter
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i think the phone is high

spring thunder
ruby otter
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-_- i want the net graph

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the final product

spring thunder
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the bottom one is the final

ruby otter
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shit

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i didnt even notice that

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ya its crct how did u do it?

spring thunder
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just taking the sign of each factor in the product and combining them

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(the 5 middle lines are my intermediary steps basically)

ruby otter
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no how did u combine in final step

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but multiplying??

spring thunder
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so yeah use the fact that even number of negative factors => the whole thing is positive

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odd number of negative factors => the whole thing is negative

ruby otter
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How did he put it directly

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i think he took on side and mirror imaged it

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thonkzoom what do u think??

spring thunder
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idk what the fuck the person did but w/e

ruby otter
#

w/e??

spring thunder
#

whatever

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(now that i think about it, w/e could also be interpreted as weekend)

ruby otter
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just listen

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i was working with another prob

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where i got |x| >A and i suddenly put
-A > X> A 😂

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took some time to realize my mistake

spring thunder
#

ewf

ruby otter
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ewf??

spring thunder
#

a mix of eww and oof

ruby otter
#

u wanna try some interesting prob??

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@spring thunder

spring thunder
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idk

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show it

ruby otter
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5n there are 2 choose one

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differentiation or domain

spring thunder
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both

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(let's start with domain)

ruby otter
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okie

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wait

spring thunder
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(wait i don't even have problems at hand thonker )

ruby otter
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how do i put alpha

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and beta

spring thunder
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in tex?

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\alpha \beta

ruby otter
#

$ if ((\alpha +1 )(\beta +1) + (\alpha -1 )(\beta +1))a + (\alpha -1)(\beta-1) =0$

obsidian monolithBOT
ruby otter
#

$ and (\alpha +1 )(\beta +1)a - (\alpha -1 )(\beta -1) =0 $

obsidian monolithBOT
ruby otter
#

Also , let $ A = { \frac{\alpha+1}{\alpha -1}} ,{\frac{\beta+1}{\beta -1}} and
B ={ \frac{2\alpha}{\alpha +1}},{\frac{2\beta}{\beta +1}} $

obsidian monolithBOT
ruby otter
#

If A intersection B not equal to NULL then find all the permissible values for the para meter a

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u der??

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@spring thunder

spring thunder
#

@ruby otter tell my internets they've been really bad

ruby otter
#

5n can u understand the prob

spring thunder
#

i 'understand' the prob

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approx. 0 ideas come to me atm tho

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+i gtg have dinner

ruby otter
#

lol i never understood the pro ever since

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so if u can help me im happy

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@spring thunder bruh u keep trying ping me when u get the answer im off now u want the 2nd prob??

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its a easy one

spring thunder
#

well just post it (i'll be off for quite a bit also)

ruby otter
#

$ if ((\alpha +1 )(\beta +1) + (\alpha -1 )(\beta +1))a + (\alpha -1)(\beta-1) =0$\
$ and (\alpha +1 )(\beta +1)a - (\alpha -1 )(\beta -1) =0 $\
Also , let $ A = {{ \frac{\alpha+1}{\alpha -1}}} ,{{\frac{\beta+1}{\beta -1}}} $ and $
B ={ \frac{2\alpha}{\alpha +1}},{\frac{2\beta}{\beta +1}} $\
If A intersection B not equal to NULL then find all the permissible values for the parameter a

obsidian monolithBOT
gaunt gate
#

does anyone here know what sec2theta is equivalent to?

#

I know that the sin2theta is equal to 2sin^2cos^2

short sorrel
#

are you given a similar identity for cos? @gaunt gate

gaunt gate
#

what do you mean namington?

short sorrel
#

do you have an identity for cos(2theta)?

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apologies

gaunt gate
#

oh no worries, I really appreciate that you tried to help

full garden
#

guys please I need some help with grade 11 functions

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how do I find the x and y intercept for this one

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please help

vale pewter
#

remember the definition of x- and y- intercept?

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o wait that's not a function .-.

spark gyro
#

is that a lowercase L

vale pewter
#

......

#

o.O

#

jesus

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ur right

full garden
#

yes that is L

spark gyro
#

ew ew ew

full garden
#

is the t = y and L= x?

obsidian monolithBOT
spark gyro
#

probably

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looks like a pendulum question

full garden
#

yes exactly it is

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i just do not know how to graph this

spark gyro
#

t would be the period and l the length

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and the usual pendulum thing is figuring out the period given the length

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so the period is the dependent variable aka the vertical axis

full garden
#

yes tubular but it is asking me to graph for Earth, Mars, and the moon

spark gyro
#

???

eternal lotus
#

o_O

full garden
#

sorry to interput you

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continue please

spark gyro
#

anyway this is just a rescaled sqrt so the only places where it will intersect the t or l axes would be t = l = 0

full garden
#

yes how do i solve for the L

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i dont know how to solve for L

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I think T=0

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but I dont know the L point

spark gyro
#

do they mean solve for l in terms of t, or solve for l given a specific value of t

full garden
#

i dont even know man the teacher just told me to graph it but I have no idea how to do that

#

please just tell me how I should graph this funcigon

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@spark gyro please help me bro

spark gyro
#

to graph a functio means to draw a picture of it

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try plugging in some values for l and typing it into your calculator

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and then draw little dots on a graph for each (t,l)

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and take a guess at what the function is meant to look like

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i recommend l = 0, 1, 2, 3, 4

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maybe also l = 1/2 if you wanna look real snazzy

full garden
#

thank you so much bro

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you are the best bro

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I really appreciate your help @spark gyro

full garden
#

guys

#

what does it mean when it asks to find the initial value of this?

eternal lotus
#

That is a velocity vs time function right

full garden
#

@eternal lotus the question says (V) is thousand of dollars , of a certain car after (T) years

eternal lotus
#

Right

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So initial value t=0

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V(0)=...

full garden
#

ohh

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so 35/0+3?

eternal lotus
#

Yes

full garden
#

so initial value means like the start value? Stephen

eternal lotus
#

Yeah basically

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initial means start

full garden
#

@eternal lotus thank you so much bro

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sorry for the dumb questions man I am not at your level

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thank you

ruby otter
#

<@&286206848099549185>

#

A , B are sets i cant put {} around them in tex

willow bear
#

you can

#

\{ and \}

ruby otter
#

-_-

obsidian monolithBOT
#

Radical Ninja:

$ if  ((\alpha +1 )(\beta +1) + (\alpha -1 )(\beta +1))a  + (\alpha -1)(\beta-1) =0$\\
$ and  (\alpha +1 )(\beta +1)a - (\alpha -1 )(\beta -1) =0 $\\
Also , let $ A = \{{ \frac{\alpha+1}{\alpha -1}} ,{{\frac{\beta+1}{\beta -1}\}} $ and  $
  B =\{{ \frac{2\alpha}{\alpha +1}},{\frac{2\beta}{\beta +1}} \}$\\
If A intersection B  not equal to NULL then find all the permissible values for the parameter a
```Compile error! Output:

! Missing } inserted.
<inserted text>
}
l.13 ...lpha -1}} ,{{\frac{\beta+1}{\beta -1}}} $
and $
I've inserted something that you may have forgotten.
(See the <inserted text> above.)
With luck, this will get me unwedged. But if you
really didn't forget anything, try typing `2' now; then
my insertion and my current dilemma will both disappear.

ruby otter
#

its fine now some one help

full garden
#

hello guys

#

is y=a(b)^x the exponential growth function?

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@ruby otter what grade is this math

ruby otter
#

you asking me??

full garden
#

ya it looks pretty hard

compact tendon
#

@full garden
1-This is called the exponential function.

ruby otter
#

what are a,b??

#

have i talk to u before??

compact tendon
#

Me?

ruby otter
#

are u pinging me in random??

full garden
#

@compact tendon there was a question asking about a rumor that has an initial value of of five. and each person that knows the rumor tells two more students the day after they hear about it

#

for the first day is it y=5(2)^1

compact tendon
#

You must be taking differential equations

full garden
#

does that mean for day two y=5(2)^2 = 100?

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@compact tendon yes exponential functions

compact tendon
#

In my opinion you are correct.

#

According to what I know.

full garden
#

@compact tendon yes it looks rational but in the answers it says in day two there will be 20 students that know

compact tendon
#

I forgot how to deal with these.

full garden
#

i dont even know where that came from

compact tendon
#

5*(2)^2

#

This is 20

full garden
#

its 100?

ruby otter
#

wait

compact tendon
#

Not 100 😂 😂 😂

ruby otter
#

lets start with n members

full garden
#

oh

ruby otter
#

next day 2n will get to know the rumor

#

so in total 3n

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where does exp func comes here

#

lemme think

compact tendon
#

It is growing exponentially

#

According to the question probably.

full garden
#

but isn

#

t

#

2*5= 10 10^2=100

#

?

ruby otter
#

its kind (3^n ) m

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n- no of days

full garden
#

ya

ruby otter
#

m - number students initially

full garden
#

oh yeah

ruby otter
#

thats the answer substitute acc

full garden
#

thank you bro

ruby otter
#

👍

full garden
#

👍

compact tendon
#

@ruby otter concerning your problem

ruby otter
#

my prob??

#

that parameter a ??

compact tendon
#

Alpha and beta

#

Yes

ruby otter
#

ya u got the answer/

compact tendon
#

I will give you a sketch

#

I did not really do it because there is a lot of work

#

You solve for one of either alpha or beta

ruby otter
#

there are 3 variables

#

thats why i find it hard to solve

compact tendon
#

a is a variable too?

#

Now this is fun

#

Please wait

ruby otter
#

ya in here a is treated variable actually its a parameter but since we dont the value

compact tendon
#

Is it arbitrary?

#

I mean, is it any real number?

ruby otter
#

it is not mentioned in the question

compact tendon
#

We assume that all of them are real

#

So that we do not restrict ourselves

ruby otter
#

ok

compact tendon
#

But beyond that...

ruby otter
#

u dont have to restrict from real numbers u have to restrict from complex nos.

thick raptor
#

what question

thick raptor
#

:l

#

set the elements equal

#

and solve the system of equations

ruby otter
#

how??

thick raptor
#

$$\frac{\alpha+1}{\alpha-1}=\frac{2\alpha}{\alpha+1}$$

obsidian monolithBOT
thick raptor
#

Add this to the equations and see if there's a solution

#

and repeat this for each element of A and B

ruby otter
#

former or latter?

thick raptor
#

?

ruby otter
#

can u explain first one or two steps

#

i will continue from there??

thick raptor
#

Well start by solving for α from that equation

ruby otter
#

how it is 3 variable?? isnt it?

thick raptor
#

?

ruby otter
#

ohh ok got it

thick raptor
ruby otter
#

wait how do u use that emoji??

thick raptor
ruby otter
#

how ??thonkzoom

#

i get -1 , -1/3

thick raptor
#

Certainly α = -1 can't be right thonkzoom

ruby otter
#

it can be why not??

thick raptor
#

actually neither of them look right

#

how'd you solve for α?

ruby otter
#

QE

ruby otter
#

PLOM u dead??

compact tendon
#

alpha cannot be one

#

Niether beta

#

Sorry for being late mate.

ruby otter
#

no prob

#

thats not a issue i cant force people to solve or help

#

take ur time

compact tendon
#

Neither -1

#

One question

#

Are you sure A is a set and is not an ordered pair?

ruby otter
#

it is a ordered pair

compact tendon
#

Wait, I am confident that you know that an ordered pair is like points of functions

ruby otter
#

well know something i said its ordered pair

#

i can be wrong coz it s not mentioned in question

compact tendon
#

If it is really an ordered pair...

#

a is a constant then.

#

Otherwise it would be absurd to figure out.

#

But wait....

#

Intersection...

#

This is indeed a set...

ruby otter
#

is it??

#

coz it is mention intersection

compact tendon
#

How would two ordered pairs intersect???

#

There is no such thing called intersection between two ordered pairs.

#

Are you familiar with the Cartesian product?

#

Or should I say, the External direct product of sets.

#

You are probably not.

#

This is not in precalculus after all.

#

But there are infinitely many solutions for alpha and beta

ruby otter
#

-_-

#

say what is cartesian prod

compact tendon
#

Alpha is -0.5a for any a not equal to 2 or -2

#

Cartesian product is a product of two sets

#

For which they form points

#

Like functions and their images.

#

Suppose R is the set of real numbers.

ruby otter
#

i know ut

#

*it

compact tendon
#

R x R is the xy plane

#

Well you do not need it at the moment

#

I found the solution

#

Something came up and I was sort of busy

#

alpha=-beta =-0.5a for any real number a except 2 and -2

#

This it what satisfies both the equation

#

And the intersection of sets not to be null

ruby otter
#

hmm

#

then

full garden
#

guys what did i do wrong here

#

this question says patient has 1 mill on Monday

serene heath
#

idek whats happenning there

full garden
#

this is the question

#

I answered a and b

#

but Idk c

serene heath
#

can you walk me thorugh exactly what u did for c?

#

because i really cant tell what u did

royal gull
#

lmfao

#

you cant cancel like that

full garden
#

yes so I had the equation y=1000000(1/x)^t

serene heath
#

it seems you cancelled the 2 with 10000 and somehow brought the x expoenetdown

full garden
#

oh

serene heath
#

but thats not how exponents work thonkeyes

full garden
#

@serene heath I just dont know how to solve question C

#

could you please help me

serene heath
#

sure

full garden
#

i think I have to substitute something in but I don't know what it is

serene heath
#

$1950=1000000 \cdot \left(\frac{1}{2} \right )^{x}$

obsidian monolithBOT
full garden
#

wait how did you do that

serene heath
#

you wanna solve for x

royal gull
#

thats what you wrote

full garden
#

ya but how did you convert it like that

royal gull
#

in your pic as well

full garden
#

it looks nice

royal gull
#

LaTeX

full garden
#

yes lemon catto keep going please

royal gull
#

do you know logarithms?

full garden
#

ohhh I didnt know that

serene heath
#

have you come across logarithms before ?

full garden
#

no

#

I dont even know what that is

royal gull
#

so I guess you could just divide by two and see waht you get

serene heath
#

well let's isolate that 1/2 term

#

so dividing both sides a by million

full garden
#

yes sir

serene heath
#

but not sure how you're gonna solve it without logs thonkzoom

#

,w 1950/1000000

obsidian monolithBOT
royal gull
#

yeah I'd say you are supposed to check what you get after dividing by 2, it won't be taht much

serene heath
#

hmm

full garden
serene heath
#

does this look familiar $\log_{2}(x)$?

full garden
#

guys is this correct?

obsidian monolithBOT
full garden
#

no @serene heath I hade never done this before

serene heath
#

is that photo maths lmao

full garden
#

ya is it not good?

royal gull
#

no

#

you wrote t/2

serene heath
#

lol

royal gull
#

not (1/2)^t

serene heath
#

its solving a different thing

full garden
#

lemon catto is the only way to solve this is by using the inverse of exponential?

barren hedge
#

Unless you want to make approximations using the regular exponential, but like why.

royal gull
#

lmao I said how you can solve it before, just read it

#

if you didnt have logs yet

full garden
#

omg okay thanks guys

#

i really appreciate it

vestal plaza
#

Can anyone help with Quadratic Functions?

patent beacon
#

#info Assume yes, no need to ask to ask

vestal plaza
idle dust
#

p = 2a +2b

#

p = 2a+ 2a +14

#

206 = 4a+14

#

192=4a

#

a=48

#

feet

#

b = 55 feet

#

area = ba

#

area = 48x55

#

= 2640 feet^2

#

@vestal plaza

#

._.

#

.-.

#

xd

vestal plaza
#

let me check

#

where you get the 55?

idle dust
#

1 is 7 longer

vestal plaza
#

oh

idle dust
#

lol

#

a is 48, then b is 48+7

#

it says in the question

#

is it right?

vestal plaza
#

yea

#

what about this one? is it the same way?

idle dust
#

oh

#

hi

#

sory

#

oh

#

ok a is height and b is width

#

so a = a and b = a+3

#

by the pythagorean theorem, a^2+(b+3)^2=26^2

#

oops i mean a+3^2

#

which becomes a^2+b^2+6b+9= 676

#

bruh

#

i keep writing b instead of a

#

but these bs are all a

#

sorry

#

let me rewrite it

#

a^2+a^2+6a+9=676

#

ok now it becomes

#

2a^2+6a+9=676

#

now we can make 1 side 0 to make it easier to use factoring techniques or other things...

#

ok now we do minus 676 on both sides of the equation

#

so 2a^2+6a-667=0

#

now this is a little complicated, so lets just use the quadratic formula

#

which is too complicated to write

#

let me just tell the answer

#

16.823482201808694

#

ok anyway

#

it says round to 1 decimal place

#

so 16.8

#

@vestal plaza

echo lynx
#

sum1 help

idle dust
#

uhh are we supposed to solve theta

vestal plaza
#

I see

echo lynx
#

no make LS = RS

#

by only simplifying LS

#

using trig identities

idle dust
#

lol

#

ok multiply both sides by sintehta+cos theta

#

now it becomes

#

the left is 1+2sinthetacostheta

#

the right is sin2theta+1

#

now minus 1 on both sides

#

2sinthetacostehta=sin2theta

#

bruh

#

ok

#

i mean

#

;-

#

;

vestal plaza
#

What about this one?

idle dust
#

girly cat boy

#

do u undrstand

#

cuz im just spilling the answers for u

#

i dont wanna just do ur homework without u being able to do it usrself after

vestal plaza
#

yea, I had another discord explain it to me also in the same time I asked this one

idle dust
#

;-;

rigid beacon
#

_>

idle dust
#

k

rigid beacon
#

@idle dust you been cheated on

idle dust
#

frik

vestal plaza
#

I got a math tutor anyways

idle dust
#

BOI

#

ok kms

rigid beacon
#

B R U H

vestal plaza
#

I am super bad at word problems and my teacher goes too fast

rigid beacon
#

Why ask here then

#

then like

idle dust
#

oh

rigid beacon
#

ask them to slow down

vestal plaza
#

because I only go to him on tuesdays not weekends and its only 1 hour

rigid beacon
#

you're paying them to teach you, if you don't understand then you're paying for nothing

idle dust
#

are u in 9th or 10th grade?

vestal plaza
#

thing is he gives homework of stuff he doesnt go into detail in class

#

I am in college

idle dust
#

wait

#

WHAT

rigid beacon
#

Yo chill

idle dust
#

ok

rigid beacon
#

different people learn math at different times

echo lynx
#

^

idle dust
#

yeash

vestal plaza
#

I havent done math for 6 years

rigid beacon
#

not everyone does calc in HS

idle dust
rigid beacon
#

in fact a minority of kids do calc in HS

idle dust
#

dont mind me

echo lynx
idle dust
#

yesh

echo lynx
#

how can this be done

idle dust
#

i dont get the point of this

echo lynx
#

with a one side solve

rigid beacon
#

1 sec

spring thunder
#

use the fact that 1 = cos^2 + sin^2

echo lynx
#

my teacher wants us to simplify one side only

spring thunder
#

done

rigid beacon
#

wait hold up

idle dust
#

but u can simplify both sides

spring thunder
#

(yeah you can tbh)

idle dust
#

this is just and identity multiplied by another identity

rigid beacon
#

yea

#

but

echo lynx
#

ik but he says he wants us only to do one side for now

rigid beacon
#

teacher wants 1 side

#

so

#

we doing 1 side

echo lynx
#

: )

idle dust
#

oK just carry us spamakin

rigid beacon
#

I hate trig identities gimme a sec

open apex
#

Interesting comversation

spring thunder
#

$$\frac{1+2\sin(\theta)\sin(\theta)}{\sin(\theta)+\cos(\theta)} = \frac{\sin^2(\theta)+\cos^2(\theta)+2\sin(\theta)\cos(\theta)}{\sin(\theta)+\cos(\theta)}$$ $$ \frac{1+2\sin(\theta)\sin(\theta)}{\sin(\theta)+\cos(\theta)} = \frac{(\sin(\theta)+\cos(\theta))^2}{\sin(\theta)+\cos(\theta)}$$

obsidian monolithBOT
idle dust
#

oh my

#

so much skills

echo lynx
#

o damn

rigid beacon
#

how the fuck people so fast with LaTeX

echo lynx
#

thx

spring thunder
#

i'm not honorable for nothing boi

rigid beacon
#

but yea that's the answer I got as well

#

just like on pencil and paper and slower

spring thunder
#

and copy pasta for ever

idle dust
#

i feel like a dum fuk

rigid beacon
#

I hate teachers being like "wOrK WItH oNe SiDe!!11!!1!!!1!!!1!"

#

like there's no point

idle dust
#

baguette

#

i dont even know why

spring thunder
#

i'm a baguette

#

🥖 arise

idle dust
#

bruh

#

i cant get anothe letter

#

0bam4 is gon3

#

play crab rave

echo lynx
#

How can I study for my trig test tmrw

#

It is on reciprocal trig ratios, trig ratios, ambiguous cases, 3d mapping problems, and pythagorean trig identities.

barren hedge
#

If it's tomorrow, work to memorize them like you would for a History test. If for an end of the course exam, work to understand the derivations/proofs.

echo lynx
#

ok ty

#

Prove that L.S. = R.S. while solving only one side

rigid beacon
#

common denominators would be my first step

echo lynx
#

cos(theta) / sec(theta) = cos^2(theta)

#

so i reduced that so far

#

ugh how do i do this

rigid beacon
#

@echo lynx cos / sec = cos^2

#

cause you have cos/ 1/cos

echo lynx
#

ik

rigid beacon
#

oh you have cos^2 = all that

echo lynx
#

this is the farthest ive got:

rigid beacon
#

man why can't we work with both sides ;-;

echo lynx
#

cos^2(theta) cot(theta) over cot(theta) - sin(theta) over cot(theta)

#

and im wondering that too lol

#

and sin(theta) over cot(theta) = tan(theta) over csc(theta)

rigid beacon
#

oh that's ez

echo lynx
#

but how do you combine that with the first term to get the R.S.

rigid beacon
#

oh eai

#

*wait

echo lynx
#

i got itttt

#

turn the first term into cos^2(theta) and the second term into tan(theta) over csc(theta)

#

then get a common denominator and combine the two numerators

#

im just confused on what my thought process should be to do those types of questions easier and quicker

barren hedge
#

From (1) to (2) I got a common denominator, and from (2) to (3) I used the definitions of secant and cotangent. From there, hopefully you see how we get to the RHS of the equation.

rigid beacon
#

oh

#

I think we both just oversimplified

#

and tried to condense stuff from there

barren hedge
#

You guys lost me very quickly from what you were saying, I can hardly read text equations like "cos/1/cos" as well as you guys xD

swift glacier
#

f(-4) would be undefined, right?

barren hedge
#

Nope

obsidian monolithBOT
soft zephyr
#

can someone help me with my hw

barren hedge
#

Gotta post the questions my dude.

soft zephyr
#

there is a lot

barren hedge
#

One at a time then.

#

So what angle of Sine gives 0?

soft zephyr
#

how do i figure that out?

barren hedge
#

Memorizing your unit circle, lol.

#

Atleast until Taylor series, and you're a computer.

soft zephyr
#

what is taylor series

barren hedge
#

Oh nothing you need to worry about until Calculus 2.

soft zephyr
#

is sin of pi 0?

barren hedge
#

Please memorize this entirely, as there's no reasonable way around it. Oh, and yes, sin(π)=0

soft zephyr
#

you have any tips to remember it >

#

?

severe verge
#

its pretty symmetric

#

you only really need the top right quadrant

#

the rest you can just get by reflecting it over y axis or x axis

#

there's this memorization mnemonic "SOH CAH TOA"

soft zephyr
#

i yes i use that

severe verge
#

sin, cos, tan are functions that relate the angle of a right triangle to the side lengths of it

#

what you do is you think of every right triangle as part of the unit circle

#

1 point at the origin, connected to 1 point on the circle

#

that's the hypotenuse

#

if (x,y) is the point on the circle, then (x,0) is the last vertex
(maybe this is really hard to imagine and I should draw a picture)

barren hedge
#

Maybe the Desmos preset graph of the unit circle could help.

#

Please do not look at the last 4 lines, they do not serve any other purpose than to form the image.

severe verge
#

the unit circle sets Hypotenuse = 1, so that
sinθ = Opposite/1 = Opposite = y coordinate
cosθ = Adjacent/1 = Adjacent = x coordinate

soft zephyr
#

y/r x/r y/x

#

what am i doing wrong here?

viscid thistle
#

inverse sin is defined where?

#

@soft zephyr

#

which quadrants

soft zephyr
#

that is all the question gies

#

gives

viscid thistle
#

what is the domain of sin^-1

#

sin^-1 = arcsin

#

you need an angle either in the first or 4th quadrant

#

where does sin(x) = -rt(2)/2?

#

there's 2 places

#

but the inverse sine function only tells us ONE of those

#

it occurs in the 4th quadrant

soft zephyr
#

so should it be 7pi/4?

viscid thistle
#

no

#

-pi/4

#

definition is tricky with these bad bois

barren hedge
#

Essentially, going forward 7π/4 is the same as going backwards (-π/4)

short sorrel
#

yeah i didnt make an active effort to "memorize" the unit circle

#

i just knew how to construct the 30-60-90 and 45-45-90 triangles

#

(and radian equivalents)

#

I "memorized" the unit circle sometime in calculus, purely naturally/accidentally

#

but an understanding of how the unit circle is constructed is enough to do it yourself

soft zephyr
#

i need help with this

barren hedge
#

Recall that sin⁻¹(-√{3}/2) is -π/3

compact tendon
#

Use Sin(A+B) formula

#

There is nothing odd with this

old marten
#

<@&286206848099549185> i need help please quick

tiny verge
#

!15m

#

!15

#

mhmm

#

okay, don't ping the helpers before 15 mins of you askig you question

#

and post the question before requesting for help

old marten
#

im sorry i havent used the server before

tiny verge
#

good idea to read the rules before using the server

#

anyway, post your question

willow bear
#

what do you need help with?

old marten
#

so Confirm that f and g are inverses by showing that f(g(x)) = x and g(f(x)) = x. f(x) = (x-9/x+5) and g(x) = -(5x-9/x-1)

tiny verge
#

right

old marten
#

ive tried a bunch of different stats to solve it but none of them are lining up

willow bear
#

uh huh... and what's giving you trouble there?

tiny verge
#

wdym diff stats?

old marten
#

i plugged in each value into the other equation and i cant seem to line up the numbers right i guess

willow bear
#

the instructions couldn't be more straightforward.

#

can you show your work?

old marten
#

like i made g(x)=-5(x-4/x+5)-9)/(x-9)/x+5)-1 then i got g(f(x))= 14x +25/14x

#

so in plugged that into f(x) to get

willow bear
#

...do you have this written out on paper?

#

it's really hard to read in plaintext

old marten
#

yes, ill send a pic

willow bear
#

do that

old marten
#

Right to left

#

Its not finished on this paper but that’s as far as I got until it stopped making sense

willow bear
#

okay just wait a minute.

#

is $g(x)$ meant to be $-\frac{5x-9}{x-1}$, or $\frac{-5x-9}{x-1}$?

obsidian monolithBOT
old marten
#

Its supposed to be the second option

willow bear
#

ok.

#

so then, how do you go from $\frac{-5\left(\frac{x-9}{x+5}\right) - 9}{\left(\frac{x-9}{x+5}\right) - 1}$ to $\frac{14x+25}{14x} $?

obsidian monolithBOT
old marten
#

My brother put them through a calculator and he said that’s what it should be

hexed ermine
#

Lol

willow bear
#

...........

#

are you not able to do the simplification yourself

old marten
#

He said he knew this stuff and he was my first source

willow bear
#

if he puts shit like this through a calculator... i would honestly not trust him much

hexed ermine
#

Hahaha

short sorrel
#

meh its kinda tedious - mind, putting it into a calculator might be even more tedious

old marten
#

Well when I multiply the -5( (x-9)/(x+5) )how do I properly simplify that?

short sorrel
#

distributive property

willow bear
#

you should, first and foremost, get rid of the fraction nesting.

short sorrel
#

but yeah

#

id knock out those fractions first

willow bear
#

because nested fractions are a great source of algebraic fuckups

short sorrel
#

make your life easier

willow bear
#

this can be done by multiplying the numerator and denominator of the big fraction by (x+5)

#

giving $\frac{-5(x-9) - 9(x+5)}{(x-9) - (x+5)}$

obsidian monolithBOT
short sorrel
#

in case you're unclear what's happening

#

(x+5)/(x+5) = 1, so this is algebraically valid

#

and yeah, it gives what ann said

#

can you go from there?

old marten
#

i understand so far but im not sure how to go to the next step

#

im sorry

short sorrel
#

distribute the -5, -9, and -1 into the binomials

#

$\frac{-5(x-9) - 9(x+5)}{(x-9) - (x+5)} \
= \frac{-5(x) - 5(-9) - 9(x) - 9(5)}{(x-9) -(x) -(5)}$

obsidian monolithBOT
short sorrel
#

if you want it spelled out deliberately

old marten
#

so would i plug that into the other equation for x in f(g(x)?

#

bc this is what we get from g(f(x)) right?

#

im sorry i just havent done this in a long time and its just making me very nervous

short sorrel
#

first simplify the above

old marten
#

ok

short sorrel
#

what function do you get?

old marten
#

-14?

#

g(f(x)=-14?

short sorrel
#

...not quite

old marten
#

oh shit

#

sorry my brain only recognized the bottom half

#

lemme try again

short sorrel
#

$\frac{-5(x) - 5(-9) - 9(x) - 9(5)}{(x-9) -(x) -(5)} \
= \frac{-5x -9x + 45 - 45}{x-x -9-5}$

obsidian monolithBOT
short sorrel
#

of course, 45 - 45 = 0, and x-x = 0

old marten
#

so we would be left with
-5x-9x/-9-5?

short sorrel
#

so we get $\frac{-5x-9x}{-9-5} = \frac{-14x}{-14} \
= x$

obsidian monolithBOT
old marten
#

ok that makes sense

short sorrel
#

one note: theres a restriction on the domain here

#

ie, one value x cannot be

#

what value is that?

old marten
#

well would the two -14 's cancel out?

short sorrel
#

yeah, -14/-14 = 1

#

and 1x = x

#

so g(f(x)) = x

#

buuuut with a restriction

old marten
#

ok so then if g(f(x))=x then would f(g(x)) just be (x-9)/x+5) still?

short sorrel
#

can you try to find the restriction first?

#

look back at the steps we did

#

where we were messing about with the x

old marten
#

am i getting caught on the wrong detail?

short sorrel
#

is there some assumption we made at some point?

#

nah, its a minor thing

#

but worth mentioning

old marten
#

um let me look

short sorrel
#

hint: we multiplied by $\frac{x+5}{x+5}$

obsidian monolithBOT
short sorrel
#

and said it was equal to 1

#

is that always true?

old marten
#

no, x could equal something other than 0 or -5

#

i think

short sorrel
#

other way around

#

anything divided by itself is 1

#

so that's always true

#

...anything except 0, that is

#

0/0 is not 1, it's undefined

old marten
#

oh so it can equal anyuthing but those values?

short sorrel
#

what value of x makes the denominator equal to 0?

#

in other words, solve x + 5 = 0 for x

old marten
#

-5

short sorrel
#

yes

#

so in our simplification process

#

we assumed $x \neq -5$

obsidian monolithBOT
old marten
#

so the restriction would be -5?

short sorrel
#

if x = -5, then we cant do what we did

#

the restriction is $x \neq -5$, yes

obsidian monolithBOT
old marten
#

ok, that makes sense

short sorrel
#

in other words, g(f(x)) = x for every value of x

#

except -5

#

it's a "small" detail but it is worth noting

#

anyway, as for f(g(x))

#

$\frac{\left(\frac{-5x-9}{x-1}\right)-9}{\left(\frac{-5x-9}{x-1}\right)+5}$

#

wait hold on

#

whered the stuff in brackets come from

old marten
#

from my miscalculations

obsidian monolithBOT