#precalculus

1 messages · Page 21 of 1

tropic coyote
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the function is continuous already

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so you can just plug 10 directly

viscid thistle
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why not?

viscid thistle
tropic coyote
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yes you can

viscid thistle
#

Not sure what you mean by this

tropic coyote
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like

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lets call D(t) the derivative of the function h(t)

viscid thistle
#

ok

tropic coyote
#

if you do the math you know that D(t) is continuous

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so you could calcualte D(10) through limits

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but its far easier to just plug in the 10 directly

viscid thistle
#

what do you mean by continous

tropic coyote
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like its graph doesnt break

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it isnt any sudden jump

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or gets weird shapes

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that make the existence of limit impossible

viscid thistle
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oh, but that's obvious

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this graph i mean

tropic coyote
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yeah for this one it is continuous

viscid thistle
#

mhm

tropic coyote
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so you can just calculate D(t) generally

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put it as a formula

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and put 10 in the formula

viscid thistle
#

lim h(t) = bla bla bla
t --> 10

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right?

tropic coyote
#

are you trying to set up the derivative there?

viscid thistle
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Yes

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i'm using the derivative formula

tropic coyote
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it should be something more like

viscid thistle
tropic coyote
#

lim h(10+Δ)-h(10)
Δ->0 ----------------- = D(10)
Δ

viscid thistle
#

so delta t reaches 0?

tropic coyote
#

yes

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but t itself shouldnt change

viscid thistle
tropic coyote
#

can i see what you tried

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it worked for me

viscid thistle
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alright

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i just gave up at the end

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lol

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also I know i put the fractions as numbers

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but whatever

wooden glen
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hey guys is this question correct?

tropic coyote
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wait

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i think i saw the mistake

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you did this right

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wait let me send photo

viscid thistle
wooden glen
viscid thistle
#

np

wooden glen
#

this isnt precalculus but can you also check this one please 💀

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im thinking its d

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not sure

viscid thistle
viscid thistle
wooden glen
wooden glen
viscid thistle
opal niche
#

👽 hi guys

viscid thistle
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i just tried 2 x's

viscid thistle
wooden glen
viscid thistle
opal niche
wooden glen
tropic coyote
#

wait why cant i send photo

viscid thistle
# wooden glen oh.

you just have to substitute x and try to see if you get the same position

wooden glen
#

im doing ACT international subjects

viscid thistle
viscid thistle
tropic coyote
#

alright let me write it here

wooden glen
#

and im doing M1 for the 3rd time tmrw lmao

tropic coyote
#

-1/30(t+Δt)^3 is part of h(t+Δt) right

wooden glen
viscid thistle
tropic coyote
#

maybe im wrong

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but thats what i saw

viscid thistle
tropic coyote
#

yeah thats wrong

viscid thistle
#

hold on, did i?

tropic coyote
#

idk

viscid thistle
#

even I'm confused

tropic coyote
#

imma check again if you wrote it as that

wooden glen
tropic coyote
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yeah you did

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you just put t as 10

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(that t=10 step is correct though)

viscid thistle
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this is what I wrote

tropic coyote
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yeah but later on

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you wrote it as -100/3 + (Δt)^3

viscid thistle
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yes, that's wrong?

tropic coyote
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yep

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do i explain why

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or do you want a quick formula to fix it

viscid thistle
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10^3 is 1000, times -1/30 is...

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wait

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where am I mistaken here?

tropic coyote
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hint: (a+b)^n usually isnt a^n + b^n

viscid thistle
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bruhhh

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ugh

tropic coyote
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remember (a+b)^n indicates multiplication

willow skiff
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it doesn't work for n = 2

tropic coyote
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so (a+b)(a+b) = a^2 +2ab + b^2

viscid thistle
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i will NEVER become a mathematician

tropic coyote
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(a+b)^3 = a^3 +3a^2b + 3ab^2 + b^3

tropic coyote
#

later on math gets cooler

viscid thistle
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I see

tropic coyote
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10+ Δt must times itself

viscid thistle
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isn't that the same?

tropic coyote
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not really

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do i explain with a cool visualization

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or do you want to just use the formulas

viscid thistle
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if (a+b) ^n , doesn't that mean that (a+b) (a+b) (a+b)

tropic coyote
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yes

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but its not ab neither (ab)^3

viscid thistle
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i thought I had factorization in check, how the heck am I still missing

viscid thistle
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and plus

tropic coyote
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yes that

viscid thistle
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ok so

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to clarify

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(10 + delta T) ^3 means that 10 and delta t times each other three times and add

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agree?

tropic coyote
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maybe you worded it wrong and thought it right

viscid thistle
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I said three times, but yeah

tropic coyote
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but this is how i would say it:

viscid thistle
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you get the idea

tropic coyote
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(10 + delta t) multiplied by itself 3 times

viscid thistle
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that sounds kind ambigious

tropic coyote
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alright good point

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let me edit

viscid thistle
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show me

tropic coyote
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alright wait

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so you know how for a number a, a^2 represents the area of a square with each side length being a right?

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like

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each side length is a

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and the area of blue square is a^2

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are you getting it?

tropic coyote
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alright so

viscid thistle
tropic coyote
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wait let me draw 2nd square

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this square has side lengths a+b

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so its area must be (a+b)^2

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right?

viscid thistle
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Yes

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ahh I see

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2ab in the corner

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i get it

tropic coyote
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so in total its a^2 +2ab + b^2

viscid thistle
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(a + b) ^2 is equal to a^2 + 2ab + b^2

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yes

tropic coyote
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yes

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you got it right

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nice

viscid thistle
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thanks

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had to refresh my memory

tropic coyote
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you could also do it another way

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with distributive

viscid thistle
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Hmm, I've heard that term but couldn't quite wrap my head around it

tropic coyote
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(a+b)(a+b) = (a+b)a + (a+b)b = a^2 +2ab + b^2

viscid thistle
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ohh

tropic coyote
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with distributive i mean distributive law

viscid thistle
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just making math more complex than it need to be

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lol

tropic coyote
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sorry if i overcomplicated this

viscid thistle
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no no, I was reffering to the law you meantioned

tropic coyote
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but basically your error was that you made (a+b)^n = a^n + b^n

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oh alright

tropic coyote
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want to try again now?

viscid thistle
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i always confuse (a+b) ^2 with (a-b) (a+b)

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for some reason

viscid thistle
tropic coyote
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alright

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tell me if you need help

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you can dm

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meanwhile imma go back to discussion

viscid thistle
warm spoke
gaunt carbon
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true tbh

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quadratic visualizations go so hard

hot root
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trying to get some help on this question, i need to find b and -b with lines passing through 12,0 and that are tangental to the circle at the origin with a radius of 6

gaunt carbon
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now the first step in a problem like this is recognizing that the radius of 6 can be used to make a triangle between the origin, point P, and (12,0)

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now since we know that the lines are tangent to the circle, we can establish some right angles

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and so by doing that we would be able to recognize a solvable triangle here

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so we're able to break this triangle out and solve for x using the pythagorean theorem since we know its a right triangle.

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this gives us an $x$ value of $6\sqrt{3}$

obsidian monolithBOT
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architecture2

gaunt carbon
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and so from there we can realize that by similar triangles we can find the other angles in this triangle

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from there we can use what we know about angles to solve for this triangle here, which gives us the value of b

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so by similar triangles we can see this

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and then we can use the 60 degree angle to find that the angle between the y-axis and point P is 30 degrees, and we can go forward from there to find b using similar triangles again

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ofc keeping in mind that this is the similar triangle we're using

hot root
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ohhh i didn’t even think of making a triangle, even though i knew CP was perpendicular to (12,0)P lol

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i’m assuming this works reguardless of where the point is because a tangental line will always make a right triangle with CP

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thank you!

gaunt carbon
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ofc

austere flame
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hey is there anyone which is at university level on math?

tender questBOT
viscid thistle
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@tropic coyote Bro, I need help

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I’m STILL!! Stuck at the same problem from yesterday 💀

tropic coyote
viscid thistle
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Hi

tropic coyote
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what happened

viscid thistle
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How tf did I even come to this conclusion!!!

tropic coyote
#

alright what happened

viscid thistle
tropic coyote
#

send photo of work

viscid thistle
tropic coyote
#

i think you did an error while calculating (a+b)^3

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not sure though

viscid thistle
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Of course I did

tropic coyote
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do i give formula for (a+b)^3

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sorry

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i dont wanna be too mean

viscid thistle
#

It’s okay

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just be mean

tropic coyote
#

alright let me send photo

viscid thistle
#

ok

warped ridge
#

$(a+b)^3=a^3+b^3+3a^2b+3ab^2$

tropic coyote
#

yeah that

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i forgot the 3's

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thanks muhammad

obsidian monolithBOT
warped ridge
#

You're welcome HSF

tropic coyote
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anyways so

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let me write how it should go

viscid thistle
warped ridge
viscid thistle
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I seriously have no idea where I went wrong

warped ridge
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Your expansion is wrong

viscid thistle
#

Hmm, how come

tropic coyote
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let me check again

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how you did it

viscid thistle
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@tropic coyote How quick did you solve this problem?

tropic coyote
#

i used another trick to find derivatives

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not limits

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so in some minutes

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its a lot harder with limits

warped ridge
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Here's one place I found

tropic coyote
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oh yeah i found an error

warped ridge
#

I can find others maybe but sorry I'm not doing well

tropic coyote
#

you did 10(Δt)^2 as (10Δt)^2

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i think

viscid thistle
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Ok so How did It was first take (a +b) (a+b) then multiply that with (a+b)

tropic coyote
#

yeah i got that part

warped ridge
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You're using the first principle arent you?

viscid thistle
#

but thats correct no?

viscid thistle
tropic coyote
#

let me send photo of my own work

warped ridge
#

$10(\Delta t)^2 \neq (10\Delta t))^2$

obsidian monolithBOT
tropic coyote
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yeah what muhammad said

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one is 10ΔtΔt

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the other one is 100ΔtΔt

viscid thistle
#

well other than using tangent lines

tropic coyote
#

the other tricks basically depend on limits

viscid thistle
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but screw that

warped ridge
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It's not about speed it's about understanding

tropic coyote
#

i dont know why it keeps getting rotated

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im trying to do it like you did

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so you can find error

warped ridge
#

,rccw

obsidian monolithBOT
warped ridge
#

There

viscid thistle
warped ridge
#

Wait

tropic coyote
#

sorry if its blurry

warped ridge
#

I can't write cause I'm literally in bed but

tropic coyote
#

ill send photo of next step

viscid thistle
viscid thistle
tropic coyote
warped ridge
#

$$h(10+\Delta t)=-\frac1{30}(10+\Delta t)^3+\frac52(10+\Delta t)^2$$

viscid thistle
#

Using limits is a tedious process

obsidian monolithBOT
tropic coyote
#

like the power rule, chain rule, the fact that derivative is linear

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etc

viscid thistle
#

speaking of, that’s exactly what I’ll learn next

warped ridge
#

Lemme actually write wait

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Bruh

tropic coyote
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trickster

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are you noticing any error in your work yet

viscid thistle
#

Hmm?

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ugh, I have to think know

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Ok lemme see rq

tropic coyote
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i did a mistake in a line

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i wrote 20Δt as 20Δt^2

viscid thistle
#

oh

tropic coyote
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its not in the cubic part though

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that part's fine

viscid thistle
tropic coyote
#

,rccw

obsidian monolithBOT
viscid thistle
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but i wrote 10 (delta T)^2 as (10 delta T) ^ 2

tropic coyote
#

yeah thats the error i found

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theyre different things

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10Δt*10Δt = 100ΔtΔt

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10Δt*Δt=10ΔtΔt

viscid thistle
#

Did I do that?

tropic coyote
#

you did the wrong version

viscid thistle
#

Ugh, I probably have to redo this entire thing

warped ridge
#

Uh I'm tired again

viscid thistle
#

it’s so easy to lose control over things

tropic coyote
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alright it should look like the last one

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do i simplify to almost last step so you can revise your own work

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or do you wanna do it yourself

viscid thistle
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I wanna do it myself

tropic coyote
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alright

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ill still have paper just in case

viscid thistle
#

okay

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so to clarify, I can do (a+b) (a+b) then multiply that with (a+b)

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correct?

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@tropic coyote

tropic coyote
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yes

viscid thistle
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Okay

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I tried learning the binomial theorem but it gave me a brain tumor

tropic coyote
#

binomial coefficients are easy to learn if you think of it as pascal's triangle

viscid thistle
#

so I’m just doing it the old way

tropic coyote
#

alright

viscid thistle
#

but Goddamn is it tedious

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and looooooong

tropic coyote
#

nah its also easy to calculate up to ( 10 k )

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calculate all of them i mean

warped ridge
#

Don't actually learn binomial expansions and do hard questions

tropic coyote
#

wanna see a cool math trick?

viscid thistle
#

actually no, it’s not so easy. Until you get to nCr ! etc then it gets complicated

warped ridge
#

They're easy the combinatorics way

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nCr is the easiest thing tbh

viscid thistle
tropic coyote
#

alright let me use pc drawing for this

warped ridge
#

Wait why do I have med lol

viscid thistle
warped ridge
tropic coyote
warped ridge
#

Idk before that I didn't care

tropic coyote
#

there i ordered the first few binomial coefficients in a triangle

viscid thistle
tropic coyote
#

see any pattern there?

viscid thistle
#

Yes

tropic coyote
#

what is it

viscid thistle
#

1’s are always outside and the middle ones add up

tropic coyote
#

yeah

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turns out the middle ones always add up

viscid thistle
#

yes

tropic coyote
#

look at it with more numbers

viscid thistle
#

ive seen it, but thats not the issue

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the problem is the nCr or whatever it means

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nCr/ ncr !

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or sum like that

tropic coyote
viscid thistle
#

are you a programmer by any means?

warped ridge
#

Ummh... No?

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I do code tho

viscid thistle
#

You doo?!

warped ridge
#

Yeah?

tropic coyote
#

yeah he did some cool things on desmos

#

mandelbrot fractal

warped ridge
viscid thistle
#

but do you code on python?

warped ridge
#

Yeah I code in manim

viscid thistle
#

I’m kinda in need for some lectures in python with physics

warped ridge
#

Why does it sound tempting for me

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'Physics'

viscid thistle
#

cool word I guess

warped ridge
#

I gotta stop gobbling libretexts on my morning walks tbh

tropic coyote
#

i should do it more

viscid thistle
#

but yeah, physics + python

warped ridge
#

I don't do physics in python

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But as HSF revealed... I do physics in Desmos

viscid thistle
#

I have no idea how python works, even though i had some python lectures in my physics class

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What’s desmos?

warped ridge
#

😫

viscid thistle
tropic coyote
#

what

viscid thistle
#

can’t lose my sanity over calculus

viscid thistle
tropic coyote
#

oh

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sad

viscid thistle
#

remind me of the hell I’m about to endure in the future

tropic coyote
#

calculus gets easier as you go

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there are some cool new tricks

viscid thistle
#

Duh

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I remember looking at limits when I was first a math newbie

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like when I was learning basic algebra

warped ridge
#

Well applied calculus is fun

viscid thistle
#

and now I’m here doing them

warped ridge
#

That's the only thing I like in physics

viscid thistle
#

Yeah but not so fun doing the math itself and losing your mind in the process 😭

tropic coyote
#

anyways if you want to i can give you photo of next steps i did

viscid thistle
#

there are more steps?

warped ridge
#

Uh what'd you do

tropic coyote
#

yeah like 3 steps

viscid thistle
#

i thought h’(t) was it

tropic coyote
#

yeah thats it

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just h'(t)

warped ridge
#

Did you put the limits?

viscid thistle
#

yes

viscid thistle
#

then substituting t with 0 and using the remainders

tropic coyote
#

yes

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next step you divide delta t

viscid thistle
#

You didn’t even factor first?

tropic coyote
#

i mean you could

viscid thistle
#

so when you divide you divide all the terms right?

tropic coyote
#

yes

viscid thistle
#

since it ain’t factored

tropic coyote
#

yep

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sorry my delta looks like a 0

viscid thistle
#

ok

tropic coyote
#

so it may be kind of confusing

viscid thistle
#

looks normal

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lol

tropic coyote
#

oh alright

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so you get left with the terms that were next to a single delta t

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and those terms are

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-(300)/30

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  • 5*(20)/2
viscid thistle
#

hold on, you haven’t multiplied with -1/30, that’s what bugs me the most

tropic coyote
#

i did though

viscid thistle
#

Why is -1/30 standing outside the parentheses?

tropic coyote
#

thats multiplying

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sorry i left the distribution for later

viscid thistle
#

yes so… don’t u remove the term after multiplying

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well i don’t know how you americans do it, but seems like we have our own methodology

tropic coyote
#

im not american

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i mean yes im in south america

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argentina

viscid thistle
#

Oh

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Ohh

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Hmm alright

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well south america is still america

tropic coyote
#

its still another country

viscid thistle
viscid thistle
tropic coyote
#

oh good

#

i was almost horrified

viscid thistle
#

You couldn’t tell?

tropic coyote
#

nah sorry

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sometimes im bad with sarcasm

viscid thistle
#

bruh

#

no problems

tropic coyote
#

anyways do you want to do the factoring yourself now?

viscid thistle
#

at last, I’ll try this dumb problem one last time

tropic coyote
#

because it seems we have different ways of doing it

viscid thistle
#

Yes

tropic coyote
#

small details though

viscid thistle
#

But wait, do you get -delta T/30 after multiplying delta T with -1/30?

tropic coyote
#

yes

viscid thistle
#

just to make sure

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Okkk

tropic coyote
#

that actually does distribute

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because its just multiplication

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no exponentiation

viscid thistle
#

yeah

tropic coyote
#

anyways tell me if you need help

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imma go to discussion

viscid thistle
#

so far this is what I have, any mistakes? @tropic coyote

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this is the (10 + t)^3

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h(10) i got 650/3 or 216.66

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if it’s wrong then just say it

tropic coyote
#

nah thats right

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at least first part

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let me check 2nd one

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yeah its right

viscid thistle
#

Ok… moving on

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@tropic coyote agree?

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the sum of h(10) is 650/3

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of what I got

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hello?

#

@tropic coyote Are you alive?

#

Sorry If I’m bothering you

tropic coyote
#

back

#

sorry i was afk went to bathroom

tropic coyote
viscid thistle
#

Alright

viscid thistle
#

and now we subtract

tropic coyote
#

yeah you substract h(10+Δt)-h(10)

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and then divide by Δt

viscid thistle
#

leaving only h(10 + T) cuz 650/3 - 650/3 equals 0

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okay

tropic coyote
#

theres a slight error there

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you also substracted part of h(10+Δt)

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because the 2nd 650/3

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comes from the expansion of h(10+Δt)

viscid thistle
#

What?

tropic coyote
#

oh sorry

#

just continue like you were doing before

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and ill tell you if theres an error

viscid thistle
#

Alright

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kinda made my heart jump

tropic coyote
#

every step up to what you showed me is right though

viscid thistle
#

Alright

tropic coyote
#

so even if you get a step wrong now you wont have to start from scratch

viscid thistle
#

now, i still have the multiplier-1/30

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I’ll multiply it with all the terms

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And this is what I’m left with

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I feel like I’m doing a mistake here

viscid thistle
tropic coyote
#

let me check if the math works out

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nah that parts wrong

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sorry

viscid thistle
#

Bruhhh😭🔫

tropic coyote
#

I MEAN

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HE

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HEY

viscid thistle
#

ok where did I blunder?

tropic coyote
#

idk can i see how you did h(10+Δt)-h(10)

viscid thistle
tropic coyote
#

why do a +650/3

viscid thistle
#

h(10) was 650/3

tropic coyote
#

yes

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also you forgot the (5(10+Δt)^2)/2 part

viscid thistle
#

💀

tropic coyote
#

alright can i tell you how i would do it

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like

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an overview

viscid thistle
#

I always forget

tropic coyote
#

summary

viscid thistle
#

Ok tell me

tropic coyote
#

ok so

#

i got (h(10+Δt)-h(10))/Δt right

viscid thistle
#

yuh

tropic coyote
#

so you got ((10+Δt)^3)/-30 + (5(10+Δt)^2)/2 - 650/3 right

viscid thistle
#

yes

tropic coyote
#

now you can pick the same terms in the expansions of both of the parts of h(10+Δt)

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to get 650/3

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so you get 650/3 -650/3

#

and youre left with only numbers that are multiples of Δt

viscid thistle
#

only numbers that are multiples of T you say

tropic coyote
#

nah Δt

viscid thistle
#

Yeah

tropic coyote
#

remember we already set t=10

viscid thistle
#

Ohh

#

huh

tropic coyote
#

so t can't appear again

#

just Δt

viscid thistle
#

you’re not using limits?

tropic coyote
#

yeah im using limits

#

but im using Δt->0

#

sorry if we're using different variable names

viscid thistle
#

when i say t im reffering to delta t

tropic coyote
#

oh alright

#

yeah then

#

what you said

viscid thistle
#

i just don’t know how you get the triangle

#

but wait

tropic coyote
#

i got big keyboard

#

real

viscid thistle
#

if t approaches 0, then how do you set T equal 10?

tropic coyote
#

i really dont get how it's an issue sorry can you like

#

explain more

viscid thistle
#

because with deltas, we’re expressing a change from t1 to t2

tropic coyote
#

yeah

viscid thistle
#

so in essence it would be like saying delta t approaches 0, because the number is, well 0

#

with comma

#

if im not mistaken

#

and making a fool out of myself

tropic coyote
#

yeah basically

#

you can treat Δt as like

#

an "infinitesimally" small number

viscid thistle
#

Yes

#

so where does 10 come from?

tropic coyote
#

from the problem

#

the original wording of the problem

#

"find the growth rate at t=10"

viscid thistle
#

t is x in this scenario

tropic coyote
#

yeah you could think of it as that

viscid thistle
#

up until this point the book im studying always sets “lim delta x approaches 0”

tropic coyote
#

just notation difference

#

small detail

viscid thistle
#

So either Im genuinely missing something or plain stupid

#

i’d bet on the latter

tropic coyote
#

the problem is

#

you cant set Δt=0 directly 0

#

until you finish solving the problem

#

because of an issue

viscid thistle
#

what issue?

tropic coyote
#

we're also dividing by 0

#

Δt

#

so you have to wait until it's in an acceptable form to set equal to 0

viscid thistle
#

yes naturally

#

but I’m presupposing we have the denominator cancelled

tropic coyote
#

yeah but that happens later

#

meanwhile you have to treat Δt as if it werent 0

viscid thistle
#

ok, so continue where you left off

tropic coyote
#

oh

viscid thistle
#

mhm

tropic coyote
#

well once youre left with only numbers that are multiples of Δt in the numerator

#

you can cancel them out with the Δt in the denominator

viscid thistle
#

yes

tropic coyote
#

and you get some terms that do still have Δt

#

and some constant terms

#

the terms that still have Δt go to 0

#

so you can just erase them

#

cancel them

#

whatever

#

but the constant terms

#

turn out to be

#

-(300/30) + 5(20)/2

#

which adds up to 40

viscid thistle
#

Mhmm

tropic coyote
#

and the limit

viscid thistle
#

alright

tropic coyote
#

lim 40
Δt->0

#

is 40

viscid thistle
#

Yes

tropic coyote
#

because Δt doesnt do anything

#

so we solved the problem

#

Q.E.D

viscid thistle
#

whatever the last part means

#

but ok I’ll try it this time

tropic coyote
#

fancy math way of saying "LETS GO PROOF SOLVED HAHA YOUR MOTHER"

viscid thistle
#

@tropic coyote

#

ok… now it should be correct

#

did I make a mistake here?

#

is my 3T^2/2 correct?

#

3 times delta t that is???

tropic coyote
#

back

#

you got 40 so i assume its right

#

congrats

viscid thistle
#

please

#

is 5 multiplied with delta t^2 + (- delta T) ^ 2 = 3delta t ^ 2 / 2?

tropic coyote
#

alright let me check

viscid thistle
#

this plus this

tropic coyote
#

yeah i think its right

#

checked more critically now

#

5Δt^2/2-Δt^2 = 3Δt^2/2

#

its right

viscid thistle
#

Finally I can sleep in peace

tropic coyote
#

congrats

#

yay

viscid thistle
#

😭

#

Such a pathetic fool I am

tropic coyote
#

do you want any resources to keep learning math

#

or do you wanna take a rest

tropic coyote
viscid thistle
#

It’s actually night now, and my time has come to sleep

tropic coyote
#

oh

#

its 6:47 for me

#

pm

viscid thistle
#

but I’m seriously considering staying up all night to read some crime & punishment and study

tropic coyote
#

i slept at 3 am today

#

but im on summer vacation so oh well

viscid thistle
#

Well it’s not exactly something a neurobiologist would recommend😅

tropic coyote
#

well lucky for you im not a neurobiologist

viscid thistle
#

I want to have a good sleep rhythm

tropic coyote
#

yeah i used to have a good sleep rhythm

#

like a week ago

#

idk why im staying up so late now

viscid thistle
#

I wanna sleep consistently at 11 and wake up at 8, but I have so low energy when I do that

#

For some reason I’m super active at nights

tropic coyote
#

same

viscid thistle
#

also I have an addiction to discord cuz i live in a dorm

tropic coyote
#

anyways

#

this isnt discussion

viscid thistle
#

so I’m pretty isolated from everyone

tropic coyote
#

so we should probably talk there

#

oh sad

tropic coyote
#

cya there

viscid thistle
tropic coyote
#

(explosion behind my back)

viscid thistle
#

😂

#

lol

#

funne

willow dagger
#

@quasi glade you are familiar with the idea of factoring a polynomial into linear polynomials right?

#

Just the concept, not the computations

quasi glade
#

yea turning some qx^3 + nx^2 + nx + p

#

into x+n or somethin

#

i got that

#

got that all day

#

theres this one specific thing i been lookin at

willow dagger
#

yeah so basically, what this relies on is the fact that you can write whatever polynomial this is in the form $f(x) = (x-a_1)(x-a_2)\cdots(x-a_n)$

obsidian monolithBOT
willow dagger
#

The product of a bunch of linear factors

#

When you multiply this out you will get $f(x) = x^n + \text{( a bunch of stuff in the middle)} + a_1\times a_2\times\cdots\times a_n$

obsidian monolithBOT
willow dagger
#

so the last factor is a product of all the roots

#

So from here you can see a restricted version of the rational root theorem:

if you have integer roots, they must divide the constant term.

#

Does this make sense so far?

quasi glade
#

i think this is stuff i know

#

but

#

Ill show what i got

#

Synthetic division i think is the part of this is confusing me

willow dagger
#

Okay, the second half is a bit weirder, but it explains the part about the denominator dividing the leading coefficient

quasi glade
#

this is an exmple problem i got coming from some video i look up

#

this whole process

#

trying to find roots of that polynomial

#

that process at the bottom i dont get at all

willow dagger
#

I'll admit I'm rusty on synthetic division, I don't think I was ever taught that

#

but I can explain the rest of the rational roots theorem if you want

quasi glade
#

idk

#

do you think i should check the help channels

#

talk in there maybe someone will know whats up

willow dagger
#

Yeah you can try, if you have a specific problem

quasi glade
#

idk this could be a specific problem but it could also be a broad concept

willow dagger
#

You won't get much success there with "can someone explain this entire broad concept" though

quasi glade
#

yea

#

i must reiterate my reading comprehension SUCKS so #❓how-to-get-help didnt really do much for me

#

maybe perhaps youtube

#

my beloved

uncut mulch
#

if you're struggling with synthetic division
start with polynomial long division

quasi glade
#

i know polynomial long division

uncut mulch
#

synthetic division is pretty much a condensed version of that

quasi glade
#

how so

uncut mulch
#

can you do polynomial long division for
(2x^3 -12x^2 + 22x - 12)/(x-1)

quasi glade
#

i can run that through rn

uncut mulch
#

and there's also a mistake in that image you posted

quasi glade
#

Idk I just copied half of what I seen

uncut mulch
quasi glade
uncut mulch
#

either what you read was wrong, or you didn't copy it down correctly

quasi glade
#

boom get long divided

quasi glade
#

like what process I was yapping about

uncut mulch
quasi glade
#

how do I get those numbers without doing the whole process

uncut mulch
#

multiply the sum to the root, in this case 2 * 1 = 2

#

then add

#

and repeat

quasi glade
#

so the term being multiplied is just z from (x-z)

#

okay

#

its clicking

#

it is beginning the long and strenuous process of clicking

#

if it would be x-6 then the thing we multiply by would be 6 leading to
2 0 22 120 at the bottom

#

which would make a polynomial 2x^2 + 0x + 22 + (120/(x-6))

#

so that wouldnt be a zero would it

#

or a root

#

or whatever

#

cuz that last addition needs to be 0 if i recall right

uncut mulch
#

correct

quasi glade
#

and x-1 would be a factor of the polynomial right

uncut mulch
#

yes

quasi glade
#

(2x^2 - 10x + 12) * (x-1) in the end

#

right

#

finally makes sense

#

i completely missed that unit last year I appreciate it

viscid thistle
#

can someone help me understand a problem that I’m facing?

hushed sphinx
#

If you'd describe your problem, the odds of someone being able to help would be much higher.

viscid thistle
#

So here is my problem

#

f(x) = -x^2 + 2x

#

find the tangent line at (2,0)

hushed sphinx
viscid thistle
#

oh my bad

narrow rain
#

Does anyone know how to do this?😭

viscid thistle
#

i dunno, all I know is SOH CAH TOA

#

lol

tender questBOT
hushed sphinx
#

They were already told that and posted their problem and moved to #calculus and got help there.

shadow summit
viscid thistle
shadow summit
shadow summit
viscid thistle
grim nimbus
#

I have a question will anybody be able gto help me

#

A can do a piece of work in 10 days and B can do the same work in 15 days. If they start working toga=ether then in hiw many days can A and B can complete the work?

narrow rain
viscid thistle
#

I have my own shi to solve

keen wharf
#

yall help

#

i cant answer this BYEEE

willow bear
jagged pecan
shadow summit
# keen wharf

Anything to the power of 0=1, so the inside of the log is equal to 0. Then solve for x.

summer ruin
jagged pecan
jagged pecan
#

But as transparent elemental said log with input 0 is undefined

jagged pecan
#

Like log base a input b means what to the base a equals b

#

So nothing to the base is equal zero

shadow summit
#

Wait nvm

#

I’m tired

jagged pecan
#

Which real number with how much power is equal zero

#

Isn't it undefined

shadow summit
#

You can just do sqrt(3)=(inside log)^1.

shadow summit
jagged pecan
#

So my solution is right

#

Or not

shadow summit
jagged pecan
#

I am saying did you got the same solutions after solving it again

shadow summit
#

Idk bro I’m in my bed at 3am listening to MF DOOM and reading manga. I do not have it in me to do mental math.

jagged pecan
#

Kk

#

,ti

obsidian monolithBOT
#

The current time for blunder69 is 10:31 PM (IST) on Mon, 11/12/2023.

jagged pecan
#

It's time for me to sleep btw

shadow summit
#

,ti

obsidian monolithBOT
#

You haven't set your timezone! Set it using the interactive timezone picker with ,ti --set.

shadow summit
#

,ti —set GMT+10

obsidian monolithBOT
#

Your timezone has been set to Etc/GMT+10!
Your current time is 07:03 AM (-10) on Mon, 11/12/2023.
Note that due to the POSIX standard, the timezone Etc/GMT+10 represents the time in GMT+10.
If your time is incorrect, consider setting your timezone to Etc/GMT+10, where the time is currently 07:03 AM (-10) on Mon, 11/12/2023.
You can read more about the standard at https://en.wikipedia.org/wiki/Tz_database#Area.

The tz database is a collaborative compilation of information about the world's time zones, primarily intended for use with computer programs and operating systems. Paul Eggert has been its editor and maintainer since 2005, with the organizational backing of ICANN. The tz database is also known as tzdata, the zoneinfo database or the IANA time z...

shadow summit
#

Eh that’s wrong

#

I’m going to bot channel

jagged pecan
#

Kk

woeful cedar
#

Bro someone help plz

jagged pecan
shadow summit
#

you can divide by 12 at the start, should make things a bit easier.

willow bear
#

you only want the solutions in [0, 2pi) not the general solution

#

can't tell if this is the only mistake but it is at least one

jagged pecan
# woeful cedar

After dividing by 12 both sides just put sin^2(x)=1-cos^2(x)

jagged pecan
jagged pecan
jagged pecan
shadow summit
#

That just feels like over complicating.

viscid thistle
#

hi guys

#

does x^(1/2) has lim at zero?

limber patrol
#

does not exist

#

because the left side limit does not exist

viscid thistle
#

x^(1/2) is square root of x. Square root of 0 is ...

rocky wind
#

Formulas of log: Let a, b > 0 and s be any real number.
definition of log: = bs = log(b). in particular, log(a) = 1 and
common log: log(a) = log₁₀(a). in particular, log(10) = log₁₀(10) = 1
change of base formula: log(b) = log (b)/log(a)
product → sum: log(ab) = log(a) + log(b)
power → multiple: log() = s log (a)

manic ledge
summer ruin
#

limit of a sum is not equal to sum of limits in this case

#

(not that limits have anything to do with infinity arithmetic in the first place)

rocky wind
# manic ledge

think: $\bZ \setminus 2\bZ = ?$, $\bZ \setminus (\bZ \setminus {1}) = ?$

obsidian monolithBOT
#

vin100

#

vin100

hushed sphinx
# manic ledge

On the other hand, the limit of -a + (a+1) is 1, and the limit of (100-a) + (a-58) is 42.
Knowing that two seqences diverge to -infty and infty is not enough to know how their termwise sum behaves.
So such limits would not be a good argument for defining a meaning for (-infty)+infty.

silk needle
#

is there any way to find the vertex here? how can I use the points?}

mental sonnet
#

hey every one i am a little confused what is considered precalculus

hushed sphinx
#

It's a chiefly American term for a loose collection of high-school topics about (single-variable) real functions that can be taught without using the concepts of derivatives.
The basic concept of function; graphing functions; asymptotes; domains and ranges; maxima and minima, monotonicity; sometimes linear functions; particular functions of mathematical importance (trig functions in radians, and their inverses, exponential functions and logarithms, rules for manipulating those). Sometimes a basic non-rigorous introduction to limits is given, at other times that seems to be postponed to actual calculus.
The name seems to indicate it is usually taught from a perspective of "don't even think this will be interesting or useful in itself, it's just a bunch of stuff you need to ~~know ~~ be able to do before you get to calculus".

astral wyvern
midnight root
shadow summit
# midnight root help

Hey, would you mind giving a translation for each question? Without knowing the question I don’t have a way to help you.

quaint heath
#

how those are equal

<@&286206848099549185>

viscid thistle
#

2CC = C+C

hybrid thunder
viscid thistle
whole spruce
#

Can someone show me how to do this question without graphing it.
A sinusoidal function crosses its minimum at ( 20 π , − 10 ) and then the next key point, its center at ( 24 π , − 8 ) .
a) Create a sine function that models this graph
b)Create a cosine function that models this graph
i know my amplitude is 2 and vertical displacement is -8, how do i find period and phrase shift?

pearl tree
#

i definitely just failed my precalc final

empty salmon
shadow summit
warped cipher
burnt hemlock
#

i think i also failed my precalc test a_cat_cry_cute_owo

pearl tree
#

I mean I won’t know until it’s graded but for sure did not study enough for the test I have an 95 currently in the class I’m just really wanting a 4.0 this semester

pearl tree
#

LET'SSSS GOOOOO i PASSED AND KEPT MY A

smoky pendant
#

can someone help me with this^

proud raven
#

A and B will be the same distance from this argument

smoky pendant
#

at pi/2?

#

thats when sin is 1

proud raven
#

sure

#

so sin(C) = max -> C=pi/2

#

how far is A from C?

#

how do we know that B and A are the same distance from C?

smoky pendant
smoky pendant
proud raven
#

,calc pi/2-pi/5

obsidian monolithBOT
#

Result:

0.94247779607694
proud raven
#

noo

proud raven
smoky pendant
#

wait so its 3pi/10

#

so i add that to pi/2 to get b?

#

since its the same distance

#

so it would be 4pi/5

burnt hemlock
lone palm
#

I'm kinda lost

shadow summit
gaunt carbon
#

yeah

#

dont forget subtraction becomes division when working with logs

opal tree
#

Make sure the coefficients of the logs are the same

loud swift
#

I need help with this problem

obtuse mulch
#

Think about what you need to have a vertical and horizontal asymptote

loud swift
#

Well how would you go about solving it

elfin loom
#

the question mentions k but it is not given in the function

#

are you sure that there is no printing error

loud swift
#

Oh the values ?

#

Its in the function at the numerator though

elfin loom
#

oh my bad

loud swift
#

This is the full problem by the way

elfin loom
#

for fx to have horizontal asymptote at y=0, the function fx must approach 0 as x approaches infinity

loud swift
#

Right

#

So plug in a big number?

elfin loom
#

no

loud swift
#

Oh

#

Well now I'm confused how would we do this

elfin loom
#

just compare the degree of numerator and denominator

#

we need y =0 for x approaching infinity

#

which means we need an x in denominator

#

degree of numerator<= degree of denominator

#

therefore k+2<5

#

k<3

loud swift
#

Wait but I thought 3 was wrong

elfin loom
#

answer can be 2 also

#

3 is indeed wrong

loud swift
#

But how would we get that answer

elfin loom
#

my mistake

loud swift
#

I did what you did

elfin loom
loud swift
#

Oh

#

Because it couldn't be equal

elfin loom
#

if there were an = sign then we would get k=3 and asymptote at y=1

#

we want asymptote at y=0

#

hence k+2<5 and not k+2<=5

loud swift
#

I see now I see now

#

Thank you so much

quasi glade
#

@woven compass you were typing

blazing cobalt
#

how do i learn limits

shadow summit
# blazing cobalt how do i learn limits

There’s a few ways, you can learn formally in your class, you can read a textbook, or you can watch videos on YouTube (Organic Chemistry Teacher and Khan Academy).

blazing cobalt
#

well

#

my teacher is pretty bad

#

the organic chemistry tutor is good

#

and khan academy i use too

#

but its confusing at times

#

textbooks dont really help

#

thing is

#

the school syllabus is pretty rushed

#

and it has the randomest stuff

#

and i have a test this week is why im concerned

shadow summit
blazing cobalt
#

rushed

#

gives us too much and unnecessary infromation

#

hard to process

#

and doesnt really care about every student

shadow summit
#

Dam that sucks

blazing cobalt
#

yeah

shadow summit
#

Limits are pretty easy though

#

If you are new to calculus the tldr of limits is just plugging numbers into the equation as they get closer to the number you want to actually plug in.

#

Take $\lim_{x\to0}f(x)=\frac{1}{x}$

obsidian monolithBOT
#

TheLord26

shadow summit
#

Just plug in small numbers

#

You might start with f(1)

#

Then f(0.1)

#

Then f(0.00000001)

#

And you will see a pattern

#

As x gets smaller f(x) gets bigger

shadow summit
#

So you then say the limit approaches infinity

#

There’s more advanced ways but for that I would highly recommend watching lectures on YouTube and working through text book questions.

shadow summit
blazing cobalt
#

i dont like limits

#

or calculus

shadow summit
#

Calculus is easy

#

Just gotta put in the time

#

It’s algebra with extra steps.

grand sedge
#

I need help

blazing cobalt
#

😭

grand sedge
#

I have a ACT coming up

blazing cobalt
#

february ?

grand sedge
#

and I heard 12% of time pre calculus question is asked on it

#

I have no clue how to solve them

#

just want some tips to solve without even looking at it

grand sedge
blazing cobalt
#

good luck

grand sedge
#

last time I got 26 on ACT math

#

hoping for 30 or 31 this time

blazing cobalt
#

for realsies

hushed sphinx
#

In February should give you some time to start studying, but if you want to "solve without even looking at it", you're out of luck from the beginning.