#help-19

1 messages · Page 185 of 1

vernal yacht
#

What triangle?

fluid tundra
#

for this particular question yes this is true

silk crescent
#

i kinda get it

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a little

vernal yacht
#

Great start btw, could you draw the partial graph of cos(1/2x) ?

silk crescent
vernal yacht
silk crescent
#

i have never heard of that method before in my life 😭

vernal yacht
silk crescent
#

this but since the range is halved now we’re only looking at the top triangle im guessing

vernal yacht
lone bison
#

ok wait that prob doesnt matter

#

for this if you do z = 1/2 * x you also have to move the interval from the "x world" into the "z world". so the new interval would be 0 ≤ z ≤ pi

silk crescent
#

do u have a strategy that doesnt involve introducing new variables?

ivory grove
vernal yacht
#

Nothing special

vernal yacht
#

Most people here suggest sketching.

lone bison
#

i sometimes think its helpful to make new variables so you can just sort of convert the problem as a simpler problem

ivory grove
lone bison
#

instead of worrying about the 1/2 factor on x just bundle it into a new variable and deal with it later

silk crescent
lean yew
#

i think right

#

if ever in doubt in this kind of problem

lone bison
#

solving cos(z) = 1/4on [0, pi] is easier

lean yew
#

substitute significant values of x into the function to see

silk crescent
lean yew
#

for example, what would you get for x = pi/4? pi/2? pi? 3pi/2? 2pi?

#

that should give you an idea

lone bison
vernal yacht
#

Alr alr, we have to come to a consensus.

Should we continue with OP’s work or sketching cosine function? Things getting messy rn

lone bison
#

like cos(pi/4) is a nice value but if you try to sub pi/4 into x on cos(x/2) you'll really end up calculating cos(pi/8)

silk crescent
lean yew
#

i'll go with the majority here

vernal yacht
lone bison
#

yeah drawing the cos function might work since you dont need to actually solve it (i think)

silk crescent
#

is that fine? okay? wrong?

vernal yacht
#

We’re not going anywhere with everybody using different methods

vernal yacht
silk crescent
#

or does it only work for specific problems like this one

#

my strat

ivory grove
#

To clarify

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your strategy is to see what points satisfy cos(theta) on the unit circle, right?

ivory grove
lone bison
#

its "how many times do these two graphs intersect within the blue area"

ivory grove
vernal yacht
lone bison
#

hm ok

silk crescent
#

my strategy is imagining that the variable affecting x (1/2, in the case of cos1/2x) is basically affecting the range, so for this question we would only look the top half of the unit circle because 2pi/2=1pi. therefore, only one solution

#

i just wanna know if thats a valid way of thinking about it or if its situational

ivory grove
#

mhm, that seems like the right way to think about it

#

because right now you're told that x<2pi

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if x<4pi for example

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x/2 would be able to hit all the values between 0 and 2pi

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and therefore your strat won't work

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@silk crescent does that make sense?

silk crescent
#

wait u said im right but then said my strat wont work

silk crescent
lean yew
#

if x < 4pi your strat won't work

#

i think that's what she meant

lone bison
#

they said it wouldnt work if the question was asking for solutions in a different interval

lean yew
#

but your x < 2pi, so you can use it

ivory grove
#

depends on what the value of x can be

silk crescent
#

damn

lone bison
#

if the question was asking for x in 0 <= x <= 4pi then x/2 could be up to 2pi

ivory grove
silk crescent
#

then i still dont understand what 1/2 is supposed to mean 💔

ivory grove
#

which means right now your strategy works

#

if it were 0≤x<4pi, then that means 0≤x/2<2pi

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which means you would have to think more carefully

#

it might not be only one solution

lean yew
#

you have 0 < x < 2pi, right?

#

so if you are now considering half of x

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the entire range is halved

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so you can divide the lower and upper bound by 2

silk crescent
lean yew
#

0/2 changes nothing
2pi/2 = pi

ivory grove
#

I'm talking abt this just in case you see similar problems in the future

silk crescent
#

alright

lean yew
#

(aka pattern spotting)

ivory grove
#

do you have any more questions?

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if not, then exp and the others can tell you the graphing method

silk crescent
#

if the range given is x<2pi and its cos1/2x i can just make the range x<pi

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but if i were given a range like

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x<6pi

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BASED ON WHAT I KNOW

lean yew
#

mhm

vernal yacht
silk crescent
#

if it was still cos1/2x the range would then turn into x<3pi

lean yew
#

correct!

#

but don't forget that your lower bound shrinks too

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for example

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if your range was -2pi < x < 2pi

ivory grove
lean yew
#

halving x gives you this range
-pi < x/2 < pi

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because the entire range shrinks by half

silk crescent
lean yew
#

similarly

lone bison
#

im not saying you have to but this is why i think its helpful to introduce new variables sometimes

silk crescent
lean yew
#

if you were given 3x, for example

vernal yacht
ivory grove
ivory grove
lean yew
#

a range of
-2pi < x < 2pi
becomes
-6pi < 3x < 6pi

#

because the entire range has been expanded by 3 times

silk crescent
lean yew
#

if in doubt, just remember one thing

silk crescent
lean yew
#

to find the new range of the function with a coefficient on the x

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multiply the lower and upper bounds (left and right of the x) by that coefficient

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if it's 1/2 x, then multiply lower and upper bounds by 1/2

#

if it's 3x, multiply lower and upper bounds by 3

vernal yacht
lone bison
#

in the original problem if you think of z = 1/2 * x and the original interval was 0 <= x <= 2pi then the z variable you defined tells you how to transform the interval
namely 1/2 * 0 = 0, and 1/2 * 2pi = pi
so the new interval becomes 0 <= z <= pi

silk crescent
#

think i got the info i need now

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hopefully…

lean yew
#

because it then also allows me to deal with cos (x + some other angle)

lone bison
#

the problem was just asking for how many solutions right? and not the solutions themselves

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in that case yeah drawing might work

silk crescent
#

alrighty

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sounds good

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probably gonna use these help channels again later today for other questions….

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but anyways

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.close

odd edgeBOT
#
Channel closed

Closed by @silk crescent

Use .reopen if this was a mistake.

vernal yacht
lean yew
#

i'll jump in if i'm around

silk crescent
#

.reopen

odd edgeBOT
#

silk crescent
#

sure why not

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hit me

vernal yacht
#

@lean yew Mind explain it?

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the heck 😂
Fine, I’ll explain myself.

lean yew
#

what

vernal yacht
lean yew
#

oh sketching

#

sure, but i'll enlist the help of geogebra

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hang on

vernal yacht
lone bison
#

desmos time

lean yew
#

oh if you have new points for me i'm down to listen

ivory grove
lone bison
#

i hate writing stuff in geogebra

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its aight but desmos just looks better

lean yew
#

so do you know the general form of the cosine graph?

silk crescent
#

yeah

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learned all about sinusoidal graphs my last unit

lean yew
#

so it looks like this, right?

silk crescent
#

yes

lean yew
#

yes i suck at mouse drawing pls no criticize :<

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ok so

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when you are told something like cos (x/2)

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if you dw to stretch the graph

silk crescent
#

oh i see where this is going

lean yew
#

you can do something very easy

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you see those numbers on the x-axis?

silk crescent
#

yeah

lean yew
#

divide all of them by 2

silk crescent
#

yea

lean yew
#

eh wait wait

#

let me rethink what i'm saying

lone bison
#

notice that cos(1/2*x) loops every 4pi not 2pi

silk crescent
#

i think i know what ur tryna do tho

lean yew
#

oh yea sorry sorry

silk crescent
#

1/2 transforms the graph by stretching it out

lean yew
#

correct

silk crescent
#

therefore

lean yew
#

but instead of redrawing the graph

silk crescent
#

the frequency decreases

lean yew
#

you multiply the values on the x-axis by 2

#

not divide

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my bad

silk crescent
#

ohh

lean yew
#

cuz doing that gives you this new graph

lone bison
#

bc 4pi after the transformation gets mapped to 2pi before the transformation

lean yew
lone bison
#

thats what divides x by 2

lean yew
#

it's the same as halving its frequency, correct

lone bison
#

yes

lean yew
#

so instead of stretching / compressing graphs

silk crescent
#

now the graph only goes through the x axis once within the range of 1<x<2pi

lean yew
#

you can instead multiply the x-values by the reciprocal of the coefficient

silk crescent
#

hence one solution

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oh yeah

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typo 💔

lean yew
#

so if you have 1/2 x

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you multiply the x-values on the graph by 2

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if you have 2x, multiply the x-values on the graph by 1/2

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you can think of it this way

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the x-values are meant to mark the period of the graph, right?

#

and frequency is 1/period

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that's why you multiply by the reciprocal of your x coefficient

silk crescent
#

okok

lean yew
#

yep, so graph sketching in a nutshell

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oh

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and this also allows you to see what happens if you have cos (x + some angle) also

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if the angle added is positive, you shift the graph to the right, or shift the x-values to the left

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i prefer to do the latter

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because then you just need to add -(angle) to all of the x-values

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vice versa for negative angles

silk crescent
#

damn

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so thats how my two trig units connect

lean yew
#

yep!

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with this

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you can even do stuff like cos(ax + y)

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apply the coefficient shift from a first

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then do + y afterwards

silk crescent
#

so basically

#

so transformations on the graph accordingly

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based on the question

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then see where the graph touches x axis

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to find solutions

lean yew
#

yup!

silk crescent
#

nicee

lean yew
#

these are all transformations of trig graphs

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there are technically two more transformations but i think you know them already

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y cos x simply makes the amplitude y instead of 1

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and cos(x) + y shifts the graph upwards by y

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or downwards if y is negative

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that's it

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the four possible transformations of sin/cos graphs

silk crescent
#

ya

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hm

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should i break the rules and post another question here

lean yew
#

be our guest

silk crescent
#

this ones about trig proofs

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apparently the answer is b

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for number 2

lean yew
#

i'm super tempted to do difference of two squares here

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but i don't think it applies

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cuz if you can

silk crescent
#

actually lemme try that

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or

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idk

lean yew
#

you can split it into (sin^2 + cos^2)(sin^2 - cos^2)

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then the first () disappears because of trig identity

silk crescent
#

oh yeah nvm i see

lean yew
#

not sure if this is legal

silk crescent
#

it is

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cuz answer is -cos2theta

#

ONE LAST QUESTION BEFORE I GIVE UP THIS CHANNEL

ivory grove
lean yew
#

oh wait

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it IS legal

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that means

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(sin^2 - cos^2) is left

silk crescent
#

yeah

#

take out negative

lean yew
#

reverse the positions of those two by sticking a negative out front

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-(cos^2 - sin^2)

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then i think you know what the last step is

silk crescent
#

i lowkey forgot difference of squares existed hehe…..

lean yew
#

i didn't initially think of applying that here

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cuz i thought it was illegal

ivory grove
silk crescent
#

yeah i do

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the reason i didnt realize is cuz i legit forgot i could do difference of squares

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initially

ivory grove
silk crescent
#

cuz

#

i havent seen any trig identities similar to this

lone bison
#

note: sin^2(x) + cos^2(x) = 1

lean yew
ivory grove
#

wait nvm

#

I thought you were referring to the previous one

silk crescent
lean yew
#

is there now

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if there is none in front

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just move the 2 to the other side of the formula

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:>

lone bison
lean yew
#

formulas are not fixed in stone. you can manipulate them for different forms

lone bison
#

oh wait wrong question

silk crescent
#

its numer 8, just to clarify

lean yew
#

from 2 sin a cos a = sin 2a

silk crescent
#

number

lean yew
#

you know that you have only sin a cos a

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so why not kick the 2 over to the RHS of the formula

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then it leaves you with what you want

silk crescent
#

rhs?

lean yew
#

right hand side

silk crescent
#

where am i taking a 2 from tho

lean yew
#

ok see

#

2 sin a cos a = sin 2a right?

silk crescent
#

yeah

lean yew
#

if i divide both sides by 2

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sin a cos a = (sin 2a) / 2

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and what's left on the left hand side?

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the expression in your question

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the rest should be pretty straightforward from here

silk crescent
#

never knew i could use identities like that

lean yew
#

oh definitely!

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identities are not set in stone

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for example right

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you know speed is distance over time?

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v = d/t

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if you do know that

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maybe you also knew that distance = speed x time?

silk crescent
#

yeah

lean yew
#

this is just a rearranging of the formula
v = d/t
multiply by t on both sides
vt = d

#

identities can be manipulated algebraically just like any other expression or equation

lone bison
silk crescent
#

wait so can i do this

lone bison
#

no

lean yew
#

nonono

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you can't divide the angle by 2

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you must divide the whole sine by 2

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so you don't get sin x

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you get (sin 2x)/2

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you get this

silk crescent
#

alralr

lone bison
#

you can consider the equivalent identity
$\frac{\sin(2z)}{2} = \sin(z)\cos(z)$

clever fjordBOT
#

exp(2) = 7.38905609893065022723…

lone bison
#

sometimes doing a change of variables makes it easier to spot patterns

silk crescent
#

oh i get it now

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got the answer

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alright thats the last of my questions for now finally 🥀

#

time to let this help channel

#

rest

#

.close

odd edgeBOT
#
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odd edgeBOT
#
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frosty sundial
odd edgeBOT
frosty sundial
#

sorry for messi handwriting

pastel orbit
#

anything you've tried so far?

frosty sundial
#

i know its a trig sub

#

but idk how to do trig sub

pastel orbit
#

the x in the numerator makes this a lot easier, actually

#

trig sub won't be necessary :p

frosty sundial
#

u sub?

strange aspen
pastel orbit
#

yup

strange aspen
frosty sundial
#

ohhh

#

i see it now

#

alr one sec

#

il be back w/ an answer

#

is it sqrt(1-x^2)

strange aspen
frosty sundial
#

oh shoot

#

i got the question right

#

btw it was ibp question i was just solving integral of vdu part

#

.close

odd edgeBOT
#
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frosty sundial
odd edgeBOT
latent scaffold
#

Split the fraction in two.

frosty sundial
#

noooo

#

partial fraction decomp?

#

oh wait no

nimble blaze
#

technically yes, but overthinking

frosty sundial
#

just 1/x^3 and -x/x^3

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and it simplifies quickly

#

is this right?

latent scaffold
#

The antiderivative of 1/x^3 is not ln|x|.

woven marlin
#

It is ln|x^3|

#

Wait

latent scaffold
#

No, one just needs to use the power rule.

woven marlin
#

That is much easier

frosty sundial
frosty sundial
#

im selling

#

this is what it shoulda been

#

.close

odd edgeBOT
#
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odd edgeBOT
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silk crescent
#

not sure what identities i can use for this question thats kinda it

nimble blaze
#

try starting with factorisation

woven marlin
silk crescent
#

because if thats what u mean i dont think thats possible

nimble blaze
#

a sub isn't required,
but it may help if you aren't comfortable working with the sin(x) present

amber veldt
#

its a factorable quadratic

#

no?

nimble blaze
#

i'm suggesting factorisation because it is definitely possible

silk crescent
#

i dont see any number i can plug in so the equation equals zero though, which i think is what ur meant to do

#

when ur factoring larger polynomials

amber veldt
#

if you have

nimble blaze
#

what numbers are you trying?

amber veldt
#

Az²+Bz+C=0

silk crescent
amber veldt
#

you look for numbers that add to B and multiply to AC

silk crescent
#

8A^4 + 2A^2 - 1

#

if we sub A=sinx

amber veldt
#

good

#

keep going

silk crescent
#

but we cant replace A with anything to make the equation equal to zero

#

right

nimble blaze
#

what numbers are you trying

amber veldt
silk crescent
#

1, -1

#

am i missing something

woven marlin
nimble blaze
#

numbers aren't limited to integers

amber schooner
#

they suggested factoring the polynomial

#

can you factor 8x^2 + 2x - 1?

amber veldt
silk crescent
#

all i remember is

#

find an integer u can replace x with

#

where the equation equals zero

amber schooner
#

what

amber veldt
amber schooner
amber veldt
#

factoring by grouping ring a bell?

silk crescent
#

i thought its different since the leading degree is 4

nimble blaze
#

oversimplification of rrt
roots aren't limited to integers

woven marlin
amber veldt
#

or quadratic formula, heard of that?

amber schooner
#

it’s a quadratic in terms of sin^2 x

nimble blaze
#

if you want to consider that,
you'd want to test +-(factors of the constant)/(factors of the leading coefficient)

amber veldt
#

but theres no reason to

nimble blaze
#

which here would also include +-1/2, 1/4, 1/8

amber schooner
#

it’s pretty straightforward to factor

amber veldt
#

because you easily find two numbers that add to 2 and multiply to -8

silk crescent
silk crescent
amber veldt
#

let B=A²

silk crescent
#

if its over 2 its different

amber veldt
#

then this is 8B²+2B-1=0

nimble blaze
#

what you have is a disguised quadratic
to avoid doing two subs, subbing for sin^2(x) instead of sin(x) would be more efficient

silk crescent
#

ok did that

woven marlin
#

Or 2(4B-1/2)^2+1/2

#

Why am I wrong?

silk crescent
#

got the answer

nimble blaze
silk crescent
#

didnt think i could substitue A=sin^2 so got confused

#

just subbed it as sinx

#

but yeah makes sense

woven marlin
silk crescent
#

.close

odd edgeBOT
#
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odd edgeBOT
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cold bane
#

How would I do these 2 questions

odd edgeBOT
cold bane
#

I have no idea where to begin

quasi sparrow
#

Do you know polar coordinates

cold bane
#

no

#

maybe ik a different name

cold bane
#

then test each option?

final ether
#

give me a condition on the radius to be tangent to the y axis

cold bane
#

what does tangent to the y axis mean

#

its parallel with it?

cold bane
#

ok

#

is the condition what the sols says

#

the radius must be same distance from center to the y axis?

cold bane
#

so we can put x^2 + y^2 = cos^2 x + sin ^2 x etc.

#

ight

#

.close

odd edgeBOT
#
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karmic stirrup
#

How do you factor? Without guessing and checking or working backwords from solving it

narrow crypt
#

Pattern recognition

karmic stirrup
#

Wdym

narrow crypt
#

Like

#

If u do enough problems, ull develop pattern recognition ability

karmic stirrup
#

But how tf am supposed to do the problems to get the patterns if its impossible to solve

copper quarry
#

Can you provide an example

cobalt coral
#

yes

karmic stirrup
cobalt coral
karmic stirrup
#

im not saying its impossible

cobalt coral
#

Oh

karmic stirrup
#

what im asking is

cobalt coral
#

so u get 3

copper quarry
#

there r methods to factorizing quadratics sir you dont have to guess

karmic stirrup
#

what are the methods

cobalt coral
#

-5(-1) ~ -5+(-1)

vivid wyvern
#

Factorize the denominator

karmic stirrup
narrow crypt
#

The unit

vivid wyvern
#

U will be able to cancel out (x-5) from numerator and denominator

narrow crypt
#

Is prolly using algebraic manipulation to solve limits gng

cobalt coral
#

If u can't solve a quadratic

Simply apply the quadratic formula

narrow crypt
#

😭

karmic stirrup
#

i understand the quadratic formula

cobalt coral
#

Yes

karmic stirrup
#

but that is basicaly solving then unsolving

cobalt coral
#

U don't understand

narrow crypt
#

Js learn how to factor. It ain’t rocket science

#

Practice a lot

copper quarry
karmic stirrup
narrow crypt
#

You’ll get used to it

karmic stirrup
#

i dont know how to facot

#

factor

cobalt coral
#

Then no need factor

narrow crypt
cobalt coral
#

Just use a calculator whatever

copper quarry
vivid wyvern
#

js find two numbers whose product gives u the constant and whi sum gives u the middle factor

copper quarry
#

bro just watch a vid

karmic stirrup
#

they dont explain it

copper quarry
#

..

#

they do??

#

u cannot tell me every single video u watched did not explain how to factorise a quadratic

vivid wyvern
karmic stirrup
#

yea

vivid wyvern
#

And the middle term is -6x

karmic stirrup
#

yea ik its simple with integers but like you almost never seen just integers

cobalt coral
#

Blud

karmic stirrup
#

like 3.02x^2+1/2x-3

cobalt coral
#

Or no

vivid wyvern
#

Dis u js make it up

cobalt coral
#

1/2x

karmic stirrup
#

all math is made up

cobalt coral
#

(3.02x^2+1)/(2x-3)

#

Like this?

karmic stirrup
#

no

narrow crypt
karmic stirrup
#

its 1/2x

#

as in

#

0.5x

#

mb

vivid wyvern
#

Sure in these case instead of digging a hole through ur head and wasting ur time
What u do is type that thing out in calc and find the values
And then use ur brain to figure the factors

cobalt coral
#

So u need to use quadratic formula

#

u can't factor it out as an integer

narrow crypt
#

wtf are u guys doing.. sully

cobalt coral
#

U got calculator

karmic stirrup
#

.close

odd edgeBOT
#
Channel closed

Closed by @karmic stirrup

Use .reopen if this was a mistake.

narrow crypt
#

The thing cancels nicely..

cobalt coral
vivid wyvern
#

Exactly

cobalt coral
#

If u can't no need to bruteforce

narrow crypt
cobalt coral
#

Just use calculator no one force u to use factorisation

odd edgeBOT
#
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Send your question here to claim the channel.

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karmic stirrup
cobalt coral
narrow crypt
#

There is no need for calculator

cobalt coral
#

Lmaoaoaoaoa

narrow crypt
#

Ffs

karmic stirrup
#

no

cobalt coral
#

Bro is jokin

karmic stirrup
#

let me clarify

copper quarry
#

,w factor 3.02x^2+ 1/2x -3

karmic stirrup
#

dawg i cant use wolfram on a test

cobalt coral
wooden python
#

what was the original question

karmic stirrup
#

ok let me clarify the exact problem im having

cobalt coral
#

Blud

#

(1/2)(x)

narrow crypt
cobalt coral
wooden python
#

how did you get 3.02 anything then?

cobalt coral
#

So it's the same anyways

If u can't factorise no one is forcing u just use formula

#

lmao

vivid wyvern
cobalt coral
#

Quadratic formula is applicable for any quadratic equation

wooden python
#

you first try direct substitution and get 0/0; this tells you that (x-5) is a factor of both num and denom

cobalt coral
#

Same goes as calculator

wooden python
#

FOR FREE!!!

#

you get one factor for free here

#

finding the other factor is not terribly hard from there

narrow crypt
vivid wyvern
#

Made

cobalt coral
narrow crypt
#

Then why are discussing if we know that it’s prolly useless?

karmic stirrup
#

i said it was made up like 40 minutes ago also give me a seccond to find what im looking for

cobalt coral
#

Bro can't create a question properly

narrow crypt
cobalt coral
#

I can create one too

wooden python
#
  • if you DON'T get 0/0, then you don't even need factorization in the first place cause you already know the value of the limit (incl. NaN)
  • if you do get 0/0, then you need to factorize but you have a leg up in it
karmic stirrup
#

ok for a situation like this were im trying to find the limit as x-> -2 how would i factor out a answer for this

cobalt coral
#

8455720x^2-6790x-35

wooden python
cobalt coral
#

Denominator

#

By 2

wooden python
#

what do you get when you do that?

karmic stirrup
#

0/0

wooden python
#

ok then you know that (x+2) is a factor of both top and bottom

#

num is 3(x+2)

#

denom is (x+2)(???)

karmic stirrup
#

ummm i would have no clue how to get that

cobalt coral
#

Just make it integer

wooden python
#

ok let's also doublecheck

#

,w 3x^2 + 5.5x - 1 at x=-2

cobalt coral
#

If u can't do factorisation directly

cobalt coral
#

Simple as that

wooden python
#

k

wooden python
karmic stirrup
#

i want a way ill understand

cobalt coral
#

ok make the denominator be integer

wooden python
#

the dumb way is (x+2)(Ax+B) = 3x^2 + 5.5x - 1, expand and match coefficients.

cobalt coral
#

Multiply both numerator and denominator by 2

wooden python
#

the smart-ish way is to notice that A=3 by looking at the leading term, and B=-1/2 by looking at the constant term

wooden python
cobalt coral
#

He don't even understand how to factorise a simple quadratic equation like x^2-5x+6

karmic stirrup
#

well

wooden python
#

is this true

karmic stirrup
#

(x+2)(x-3)?

cobalt coral
#

Scroll the chat up

karmic stirrup
#

or

#

wait

#

no

cobalt coral
karmic stirrup
#

no

wooden python
#

you need to review your factorization m8

karmic stirrup
#

i didnt read ur thing i thought it was the one a wrote eailer

copper quarry
cobalt coral
#

When u can't even factorise it fast now u teach a more complicated way I'd say ()

karmic stirrup
#

(x-2)(x-3)?

#

i know how to factor simple things like that

#

the reason i got it wrong is becuase u copyed one a wrote eariler but u changed it but i thought it was the same

cobalt coral
#

Ok

wooden python
#

have you heard of such things as:

  1. vieta's formulas
  2. polynomial division
  3. the concept of equating (or matching) coefficients
karmic stirrup
#

this one was simple i can do simple ones

#

nope

wooden python
#

not a single one of these?

#

sum and product of roots? no?

narrow crypt
karmic stirrup
#

ummm

cobalt coral
karmic stirrup
#

the 3rd one sounds familuer

cobalt coral
#

Since u need to know one of the roots

wooden python
#

i was casting a wide net here.

wooden python
#

so do you want me to go over my point again

karmic stirrup
#

um

#

which point

wooden python
#

i was trying to explain how to find the other factor

#

i.e. how to solve the following problem:

the polynomial 3x^2 + 5.5x - 1 has (x+2) as a factor. find the other factor.
karmic stirrup
#

oh

#

uimm

wooden python
#

i want a straight "yes, go over it again" or "no, shut your yap about it" answer

karmic stirrup
#

go over it again

wooden python
#

k

#

so first off

karmic stirrup
#

u did like (x+2)(ax+b)

#

or

#

not

#

ax

wooden python
#

yes

#

the other factor is going to have degree 1

#

do you need that explained in detail or are we good

cobalt coral
karmic stirrup
#

i dont know what degree 1 means

wooden python
wooden python
karmic stirrup
#

oh

#

that

#

yea

cobalt coral
wooden python
cobalt coral
wooden python
#

i'm a she.

cobalt coral
#

In order to do polynomial division u need to guess one root forst

wooden python
#

i'm a she.

cobalt coral
#

She

wooden python
#

why tf are y'all skulling me over this.

cobalt coral
#

some kind of unexpected

wooden python
karmic stirrup
#

cuz he is a non gender specific term for the most part when typing

bitter folio
wooden python
#

HE IS NOT A NON-GENDER-SPECIFIC TERM

bitter folio
#

like i have a blue diamond and i am he/him

wooden python
#

IT IS CLEARLY FUCKING MASCULINE THANK YOU VERY MUCH!

bitter folio
#

pls dont misgender people in future thanks

karmic stirrup
#

if u dont know or think about someones gender everyone just says he or him

cobalt coral
karmic stirrup
#

becuase it dounds

#

sounds worse to say

bitter folio
cobalt coral
#

Say 'it'?

karmic stirrup
#

it

wooden python
#

no

bitter folio
#

but lets get back to the question

wooden python
#

they/them

cobalt coral
#

Or ask ur gender before chatting

#

Oh what's ur sex

wooden python
#

is the default if you don't know someone

bitter folio
#

pink diamond or blue diamond

#

or any other colour

cobalt coral
#

They means everyone not include urself

karmic stirrup
#

look ive been banned from a discord before for calling someone a them

cobalt coral
bitter folio
cobalt coral
#

This is 2025

wooden python
#

pink diamond means she/her, blue diamond means he/him, yellow means they/them, grey means anything goes

cobalt coral
#

Not 1005

wooden python
#

ok should i call the mods

bitter folio
karmic stirrup
#

no plz

cobalt coral
#

Oh

wooden python
#

or can we all put our big girl/boy/etc. pants on and get back to the question?

karmic stirrup
#

i mean u were the one complaining but plz do go ahead im still confuzeld

cobalt coral
#

Lmao

#

Bro started and ended it

wooden python
#

DON'T CALL ME BRO

cobalt coral
#

What

wooden python
#

<@&268886789983436800> this is like the 3rd offense now

wooden python
karmic stirrup
#

bro is 100% gender neutrol

cobalt coral
#

I thought bro usable on every gender huh

wooden python
#

well newsflash no the fuck it don't.

cobalt coral
#

Okok let's continue

#

Shall we

bitter folio
#

ann dosent like it -> dont use it on her

karmic stirrup
#

ive called my mom bro like 50 times

bitter folio
#

simple

wooden python
#

gurghruhr.h

#

ok

#

anyway my point is
i didn't guess a root.

cobalt coral
wooden python
#

the knowledge that x=-2 is a root of the quad

#

was NOT A GUESS

cobalt coral
#

Then

#

Ur sense

wooden python
#

no

cobalt coral
#

Then

karmic stirrup
wooden python
#

no 6th sense no nothing

cobalt coral
#

Then how u got it

wooden python
#

i know it's a root because plugging x=-2 in yielded 0/0

#

and the REASON we bothered to do that is that we're finding the limit as x->-2

karmic stirrup
#

oooo u smart that actualy makes sense

cobalt coral
#

For some question it doesn't mean that x=-2 is a root

narrow crypt
cobalt coral
#

It's not applicable for every question

wooden python
#

therefore it is not a guessing matter at all that -2 is a root, capisce?

cobalt coral
#

Yk

wooden python
bitter folio
karmic stirrup
#

so if i have a limit for x->a can i factor out (x-a) comfortably?

viscid flint
#

(i think everything's already been said but yea pls respect people's choices & differences, especially here where we make it nice and easy with icons)

cobalt coral
#

U can direct know the root by substitute into the eq and get 0/0, bcz u are doing a school question

wooden python
cobalt coral
#

So it's basically a pattern for question

karmic stirrup
#

umm

cobalt coral
#

Concept? No

wooden python
#

if:

  • you are working with a limit as x->a, AND
  • the numerator or denominator is a polynomial, AND
  • you get 0/0 when plugging x=a in,
    then yes, that polynomial can have (x-a) factored out of it.
karmic stirrup
#

the blue diamond assumed im male help

cobalt coral
#

Trick yes

wooden python
karmic stirrup
#

wait

cobalt coral
#

Hi I'm gurl

#

Call me she from now on else imma beat ur ass

#

Thanks

viscid flint
#

sigh

karmic stirrup
#

for the num and denomiator is it either both or one has to be polynomial

wooden python
#

whichever one is a polynomial, that's the one you can factor (x-a) from.

#

it may be that you have a polynomial on the num and something else on the denom (or vice versa)

#

what im highlighting here is specifically the thing where like

#

the context of the limit question lets you know a root, and hence a factor, for free

#

WHY AM I STILL GETTING SKULLED.

cobalt coral
#

How u gonna do

karmic stirrup
#

oh could u help me with a situtaion where u wouldent get a factor for free

wooden python
#

... what.

cobalt coral
#

Oh every polynomial has a root

viscid flint
#

@cobalt coral you don't appear to be helping. Leave.

narrow crypt
#

Omg if it’s asymptote, it won’t be in indeterminate form

#

Ffs

cobalt coral
#

y

wooden python
#

@karmic stirrup can you stop reacting with nerd emoji and others all over my messages?

#

it feels disrespectful.

karmic stirrup
#

ok

wooden python
#

i'm trying to help you and you fucking clown on me?

#

i'm not your mate to banter with, jsyk.

karmic stirrup
#

no not realy

#

i mean you can stop helping if u want im not forcing u

wooden python
#

ok so like

#

do you have a question on hand that you need to do

karmic stirrup
#

sure one sec there is one

cobalt coral
#

yi

wooden python
#

ok right

karmic stirrup
#

i understand

wooden python
#

so this one's got roots.

#

and there's a different technique that you will wanna use to make this one happen.

sinful grove
#

Why are we still letting this happen, theyre being very misogynistic and one of them is still expecting help. Like what the hell

karmic stirrup
#

im supposed to multyply both sides by root(2x-5)-1

wooden python
#

sqrt(2x-5)**+**1

karmic stirrup
#

yea

wooden python
#

yes

#

the denominator is just bare x-3 so there's no factorization to be done there

#

do you understand what to do after multiplying by the conjugate?

wooden python
#

as for troller123 i just blocked her ass.

karmic stirrup
#

well u would get 2x-5-1/(x-3)(root(2x-5)+1) right?

cobalt coral
wooden python
cobalt coral
#

Also her concept is kinda wrong I just explain

wooden python
wooden python
clever fjordBOT
wooden python
#

numerator is 2x-6, a.k.a. 2(x-3).

karmic stirrup
#

yea so u have 2 over the root and +1 but thats where i get stuck

wooden python
#

at this point you just plug x=3 in...

#

you've gotten rid of the sources of 0 in both num and denom

karmic stirrup
#

but its still 2/0 init?

wooden python
#

no it's not

#

work it out

karmic stirrup
#

oh yea ur right

#

because its not -1 its +1 now

wooden python
#

the whole purpose of this conjugate rigmarole is to get rid of unsafe factors and replace them with safe ones.

karmic stirrup
#

thanks i just relized why it was going so array thanks for the help

wooden python
#

god ngl troller had some nerve.

#

i hope she steps on a billion legos.

#

but ok whatever.

#

!done

odd edgeBOT
#

If you are done with this channel, please mark your problem as solved by typing .close

karmic stirrup
#

.close

odd edgeBOT
#
Channel closed

Closed by @karmic stirrup

Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

leaden flicker
#

Hi there, I'm developing a game that is a clone of breakout. I thought it would be a relatively simple game to clone and so far it has been. The biggest issue I've been having is in doing a form of continuous collision detection for the ball. Please forgive me for my sloppy use of mathematical terms, I'm not super confident on the language and terminology in English.

I've made a little illustration first of all to show the situation and how far I've gotten so far; I included it.

My ball is represented as the circle at point C with a radius of r, it is moving towards point D which I've represented as a vector V. On the way there, it will intersect the boundary wall, represented as the line AB. The intersection of the line CD and the line AB is marked as point E. I'm good up to this point.

The problem begins here. Now that I've found point E I know I can find the normal of the line AB and multiply it by r to create the triangle in the second image.

My question now is, how do I find the hypoteneuse and the vertical line so that I can find point Q and point X?

Thanks!

gritty spire
#

you have to use a ball not a circle right

#

oh no, i confused the game lol

#

OHHHH atari breakout

leaden flicker
#

yes!

#

It's a 2D game so it's just a circle.

gritty spire
#

most game engines have collision detect right

leaden flicker
#

they do but that is not an option for me here as I am not using a game engine, and I want to understand this mathematically.

gritty spire
#

so i was confused by the question sorry i cant help 😦

odd edgeBOT
#

@leaden flicker Has your question been resolved?

woeful vine
leaden flicker
#

Yes, I suppose that's the same thing as knowing where Q and X are.

woeful vine
#

we have a right triangle where we know one of the sides (r) and an angle (θ), does any trigonometric formula come to mind?

leaden flicker
#

Well I can vaguely remember that I had to solve this exact problem in high school but that's over 15 years ago. So no, they don't; it's all on the tip of my tongue.

woeful vine
#

in general it is true that
side = hypotenuse ⨯ sin(opposite_angle)
side = hypotenuse ⨯ cos(adjacent_angle)

and if we compare two sides
side = other_side ⨯ tan(opposite_angle)

leaden flicker
#

Hmm, so in this case hypotenuse = tan(θ) / r?

woeful vine
#

if you notice there's never hypotenuse and tan(angle) at the same time in any of which I wrote

leaden flicker
#

ah right

#

then it would be vertical = r * tan(θ) and then with thathypotenuse = sin(θ) / r?

woeful vine
#

you can use any formula to compute the one point you really want, but you have to use them correctly
in our case the side of length r is adjacent, and not opposite, to θ so the relation between r, θ and the hypotenuse goes through cosine, and not sine
r = hypo ⨯ cos(θ) --> hypo = r/cos(θ)

leaden flicker
#

ah..

woeful vine
#

but the other you wrote is correct

leaden flicker
#

Think I need to refresh myself a bit on the trigonometric functions, thank you :)

woeful vine
leaden flicker
#

Right, sorry

#

.close

odd edgeBOT
#
Channel closed

Closed by @leaden flicker

Use .reopen if this was a mistake.

odd edgeBOT
#
Available help channel!

Send your question here to claim the channel.

Remember:
Ask your math question in a clear, concise manner.
Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
• Type the command .close to free the channel when you're done.
• Be polite and have a nice day!

Read #❓how-to-get-help for further information on how to ask a good question, and about conduct in the question channels.

mystic saffron
#

that is 5, please verify

odd edgeBOT
twilit mulch
mystic saffron
#

ye

south plume
mystic saffron
#

r^2

twilit mulch
#

r^2 + 4r^2 = 25

mystic saffron
#

ye

#

r^2=5

twilit mulch
#

Yah

#

just sqrt both sides

mystic saffron
#

no

#

u need area

twilit mulch
#

Nvm r^2 is the area

mystic saffron
#

and area in terms of r is

#

ya

twilit mulch
#

Yah the area is 5

#

There u go

mystic saffron
#

btw this

#

so

#

i used pythag.

twilit mulch
#

Pythagorian too

mystic saffron
#

and found that

#

ye

#

1st base is 16 2nd. is 33

twilit mulch
#

epic

mystic saffron
#

so diff is 17.

#

ok this

brittle plinth
#

quick formula

twilit mulch
#

Use similiar triangles

mystic saffron
#

ok

brittle plinth
#

BX^2 = XA.XC

mystic saffron
#

i see 3

twilit mulch
#

BX^2 = XA.XC

mystic saffron
#

what is the dot in XA.XC

twilit mulch
#

It means multiplication

mystic saffron
#

oh

twilit mulch
#

Its popular in asia

mystic saffron
#

ok

#

is x or *

#

so BX^2 = 60

twilit mulch
#

yea dot means multiplication

mystic saffron
#

root(60)

#

2root(15)

twilit mulch
#

Epic

mystic saffron
#

for this i have an idea

#

find the height

#

and then calcualte legs

#

so height is

#

18

twilit mulch
#

mhm

mystic saffron
#

so if u split triangle in half

#

the sides wud be 12, 18 ,leg

#

?

#

is height 18?

twilit mulch
#

How would you know the height intersects the mid point of given base

mystic saffron
#

its icoceles

#

u got me thinking

twilit mulch
#

hmmm

#

Oh ya mb

#

I misunderstood

mystic saffron
twilit mulch
#

Ya

mystic saffron
#

so is it root(468)

#

for leg

#

$6root(13) + 6root(13) + 24 = 12sqrt(13)+24$

clever fjordBOT
#

✪Royal✪

mystic saffron
#

ye we need someone to verify

mystic nova
mystic saffron
#

mb

brittle plinth
#

$6 \sqrt{13}+ 6 \sqrt{13} + 24 = 12 \sqrt{13}+24$

clever fjordBOT
#

C∆rbonizeD

mystic saffron
#

for this question i bet u use similar triangles

brittle plinth
#

yep

mystic saffron
#

label the intersection of AD and BC as x

#

let me do that rq

brittle plinth
#

actually there's a way that you don't need to use similar triangles

mystic saffron
#

oh

#

we do similar triangle way 1st

brittle plinth
#

yea sure

brittle plinth
#

ah I misread

#

Ok continue

mystic saffron
brittle plinth
#

go on

mystic saffron
#

the

#

then they similar AA congruency

#

ratio of sides is 11/4

brittle plinth
#

yep

mystic saffron
#

so AX/DX = 11/4

#

AX+DX = 30

#

so

#

4AX + 11DX = 30

#

wait

#

AX is 22

#

DX is 8

brittle plinth
#

exactly

mystic saffron
#

then BX is sqrt(22^2-11^2)

#

CX is sqrt(8^2-4^2)

#

so

#

$\sqrt{363} + \sqrt{48}$

clever fjordBOT
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✪Royal✪

mystic saffron
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thus 11root(3) + 4root(3)

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so 15root(3)

brittle plinth
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nice

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wanna know another way to solve this?

mystic saffron
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oh

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15 is AE