#help-0

1 messages · Page 722 of 1

viscid cove
#

yeah that's a typo. Do you happen to know how that turns into $$(1+1)^{n-1}$$ ?

ocean sealBOT
#

drunkzurg

fathom violet
#

binomial theorem

viscid cove
#

i'm learning it rn, could you elaborate?

fathom violet
#

well you know (a+b)^2 = a^2+2ab+b^2

viscid cove
#

uh huh

fathom violet
#

thats the same as (a+b)*(a+b)

#

a binomial expansion or the the binomial theorem

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but you can put any number as the exponents

viscid cove
#

there are two 1's, i assume its some row in pascal's triangle

#

oh, one sec

fathom violet
#

ye

viscid cove
#

wait, where did we get the number of terms in the bracket as n though? i'm lost

fathom violet
#

okay first you just factor out n out of all the terms of the sum (in front of the brackets)

#

then you are left with the sum 1 + 2(n-1)/2! + 3(n-1)/3!+ ...

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then you can reduce the factorial

viscid cove
#

so in the end term(n+1th) , there would be a n! at the top and maybe it was canceled by n! at the bottom?

fathom violet
#

ye

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nah you right

viscid cove
#

wait, i saw that

#

why is it not (n-1)! ?

#

its starting from n(n-1)..... nevermind

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well that's all, thanks for the help!

fathom violet
#

aite

vague jolt
#

If two different functions are bijective and have the same domain do their codomains have the same cardinality?

alpine sable
#

Help

sleek elbow
wind bane
alpine sable
native temple
#

2+2 =?

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3+5=?

alpine sable
sleek elbow
#

you are very wrong on discord if you cant add 2+2 imo

alpine sable
#

LOL

#

They prob joking

#

U

#

H

glass lichen
#

yeah it's a troll

ionic jewel
#

if you can't do basic arithmetic you need to get an addition table and memorize it

#

or use your fingers

sleek elbow
#

if you can't do basic arithmetic you need to get an addition table and memorize it
or use your fingers

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^^

alpine sable
#

<@&286206848099549185>

tight locust
#

QUESTION:

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consider the infinite polynomial:

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$f(x)=\prod_{n=-\infty}^\infty (x-n)$

ocean sealBOT
#

EndTimes

tight locust
#

would this be equal to the sine curve?

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sin(pi*x) specifically

ionic jewel
#

how did you get that?

tight locust
#

it's not nevermind

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this polynomial just turns into a bunch of vertical lines

ionic jewel
#

i see

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i thought it might expand out into the taylor series of sin or something lol

tight locust
#

it explodes between the zeros

ionic jewel
#

yeah wait it doesnt work for any integer x

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because the entire expression just goes to 0

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ah i see what you mean

glass lichen
#

It has the same solution set as sin(pi*x)

tight locust
#

it is supposed to have zeroes at all integers

ionic jewel
#

it does have zeroes at all the integers

#

just the rest of it doesnt work

tight locust
#

so how do you make an infinite polynomial behave nicely?

glass lichen
#

you... dont

tight locust
#

wdym?

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plenty of functions are defined as infinite polynomials

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but most of them are sums instead of products

glass lichen
#

well yeah, those are taylor/mclauren series

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those are constructed to be elementary functions

lapis sonnet
# tight locust would this be equal to the sine curve?

Check out this video https://youtu.be/WL_Yzbo1ha4 Euler used this to prove a bunch of formulas about pi. You just need to include a coefficient

Today we derive them all, the most famous infinite pi formulas: The Leibniz-Madhava formula for pi, John Wallis's infinite product formula, Lord Brouncker's infinite fraction formula, Euler's Basel formula and it's infinitely many cousins. And we do this starting with one of Euler's crazy strokes of genius, his infinite product formula for the s...

▶ Play video
#

(He introduces it at around 4 minutes in the video)

split slate
#

I've already gotten that θ is 90, but what about α?

split slate
#

But I just don't know the reason behind it

tight locust
#

yeah it's 40

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not 33

cerulean comet
#

Oh

tight locust
split slate
#

OH!

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DANG IT

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HOW DID I MISS THAT?!?!

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Bruh

cerulean comet
#

Oh yeah I missed that when I said 33

tight locust
#

it looks like a right angle but i can't recall the theorem or whatever you're supposed to use

umbral igloo
#

this is kind of a weird question but
are there any equations that look like breaking ocean waves (im not talking about sine / cosine waves)
kind of like these:
(Hopf equation)

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(burgers equation)

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please use the reply button, thanks! 🙂

dark granite
#

I chatted with my physics prof about this last year, and he pretty much said such a wave would only occur using functions like sin/cos

umbral igloo
dark granite
#

I don't think so because cos/sin waves are pretty symmetric with respect to their peaks so the slight angle on the curves you attached (in the first screenshot) don't occur like that.

umbral igloo
#

oh alright, thanks!

dark granite
#

Try messing around with different values of $\alpha, \omega, \phi$ for $\alpha\sin(\omega t+\phi)$ and $\alpha\cos(\omega t+\phi)$.

ocean sealBOT
#

logician_pdx

dark granite
#

That might give you some more intuition on what really happens @umbral igloo

sudden crypt
#

I wonder if there are cool f with sin(f(x)) because if f gives low values, its more streched out and if its high, it condenses more

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maybe there are cool ones with polynomials?

dark granite
#

possibly yeah

split slate
umbral igloo
#

kk ill give it a try, thank you

whole moat
#

Anyone help me with this.. I did it but I'm kind of confused if I'm going in the right steps

split slate
#

So, any angle at the circumference subtended by the same two points will be the same, this θ is also equal to 90°

manic glade
#

which of these is the standard way to notate an equivalency class?

primal furnace
#

someone help

#

help me get an expression for the numerator pls

tight locust
#

have you found the roots

primal furnace
#

no

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i got the ansewr

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dw

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1/a^2+1/b^2+1/c^2=(1/a+1/b+1/c)^2-2(1/a+1/b+1/c)

sudden crypt
ionic jewel
#

,w roots x^3-2x^2-4x+6

fringe yoke
#

How do you solve that ?

ionic jewel
#

hmm, didnt think it would be that easy, not sure what the trick is though

sudden crypt
#

not even real roots lul

ionic jewel
#

dont see a way to convert in this case

fringe yoke
#

Usually I am able to use factoring by grouping for cubic stuff

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but it doesn't seem to work here

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wtf

ionic jewel
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it doesnt usually work either

fringe yoke
ionic jewel
#

your teachers just give you the very small set of cubics that can be factored by grouping

fringe yoke
#

Hmm how could we solve this

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well we know P(x) = (x-a)(x-b)(x-r)

indigo jetty
#

this problem is meant to be solved using vieta's formulas

fringe yoke
#

oh my

fleet glacier
#

(a²+b²+c²)²?

ionic jewel
#

ah i dont happen to know vieta's formulas that would be quite the problem

fringe yoke
#

maybe I can manipulate the cubic formula to get 1/a^2 + 1/b^2 + 1/r^2

sudden crypt
#

actually I think it has something to do what I did earlier in #help-8

fleet glacier
#

Newton's sums could work

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I can't do it rn

sudden crypt
#

I also think abc = -6 via Vieta or soenthing

fleet glacier
#

Yes

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try (ab+ac+bc)²

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Man I wish I had paper

sudden crypt
#

a+b+c = -2, ab+ac+bc=-4 and abc=6 should be right, can somebody check?

fringe yoke
#

,ask 1/(-1.866^2) + 1/(1.211^2) + 1/(2.655^2)

sudden crypt
sudden crypt
#

so from the polynomial we have a+b+c=2, ab+ac+bc=-4, abc=-6
(ab+ac+bc)^2-2abc(a+b+c) = (ab)^2+(ac)^2+(bc)^2, which should be 40. Now 1/a^2 + 1/b^2 + 1/c^2 = ((ab)^2+(ac)^2+(bc)^2)/(abc)^2 = 40/36 = 10/9

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Help me its 4:20AM and Im on my phone and cant sleep

alpine sable
#

(Gamma^2*Beta^2) + (Alpha^2 * Gamma^2) + (alpha^2+beta^2)
/(Alpha beta gamma)^2

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@sudden crypt solve for this you will get the answer

sudden crypt
#

what are you talking about I already solved the problem?

alpine sable
#

Ohk

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Sorry lmao

alpine sable
sudden crypt
#

oh lmao

alpine sable
#

What does it mean by interchange the role of x and z

tight locust
#

i mean it literally gives you the inequality

alpine sable
void swift
#

Hello, how can I prove that a quartic polynomial can only have at most one line tangent to it at 2 distinct points?

#

I've determined already that the quartic will need to resemble an "M" or "W" shape on the graph for the line to be tangent at 2 points.
I also think that the Mean Value Theorem might have something to do with this, but I don't know.
I've racked my brain drawing graphs this afternoon trying to figure out how to prove this but have yet to get anywhere blobsweat

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This is the last question from this week's calc homework. The extra hint I received was to "consider doing interval analysis" but I'm just not getting it...

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Aren't there other (empty) channels for you to use? @vague jolt

wind bane
#

You can't even do that composition unless B is a subset of A

sage vale
#

what is a gof

wind bane
#

And no. It would be g o f : A to C

void swift
wind bane
#

have you considered what happens if you have two lines tangent to the graph, each tangent at two distinct points

void swift
#

Where on the graph would those points you mention be located?

wind bane
#

the points of tangency…

void swift
#

Well, yes, of course I know that, I'm asking are you asking me to think about those 2 points in any specific location

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On the extremum? Close to the extremum?

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I know that in the scenario I discussed the line can be tangent either to the 2 extremum or close to them, but I've no way of proving it

wind bane
#

if they are not tangent at the extremums, then you can use the intermediate value theorem to show that it is either tangent to one or more than two points i beleive

primal furnace
#

guys

#

i found out how to do it

void swift
#

The second scenario

primal furnace
#

i solved it by

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ill send photo

fringe yoke
#

ye

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not cubic

primal furnace
#

its kinda the same thing

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u can get a general form

wind bane
primal furnace
#

ill send in a sec

void swift
#

In between the two? I don't think that's possible

wind bane
wind bane
void swift
#

To pretend that 2 lines is possible

woeful pulsar
#

You can always make that line horizontal by considering y'=y-mx

void swift
#

I can show that if the y-value of the two extremum are the same, then there can not be >1 line

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According to rolle's

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the problem part is asymmetric quartics

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i will try to make 2 lines. maybe algebra? thinkingbread

woeful pulsar
#

to make your line horizontal

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essentially you are applying a shear transformation which preserves tangency

paper bay
#

is the channel free for me to ask my doubt?

void swift
#

I don't know if I'm making any sense if I'm just spewing nonsense

void swift
#

Like in a system of equations

woeful pulsar
#

use that gradient of the line to modify your generic quartic

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such that the tangent line becomes horizontal

primal furnace
primal furnace
#

also @fringe yoke if ur curious

void swift
#

Sorry for the silly questions, I've never heard of shearing before

fringe yoke
#

But holy shit

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the cubic formula

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is so fuckign tedious

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I dont follow that well

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but it's ok]

primal furnace
#

no cubic formula needed :)

forest wasp
#

I'm looking at this question right now but after viewing the solution I'm still a bit confused about one section of the solution. How do you know that the function must be recursive? (I'm confused about why f(n) must equal f(n-1) + f(n-2)). Thanks in advance

woeful pulsar
#

if we have a tangent line y=mx+c, then we consider the transformation y'=y-mx. So we use this transformation for the graph and the tangent line

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yeah it becomes y=constant

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something like this

forest wasp
woeful pulsar
forest wasp
#

ah, yeah I think I see it now, ty 🙂

hexed bloom
#

anybody care to help me out in this?

ionic jewel
solid lintel
#

I want to draw a picture made up of a few ellipses, a semicircle and a few line segments as a single equation in a graphing calculator

#

I know how to draw a single line segment in them

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But that method removes everything left or right of the segment

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I came up with one theoretical method involving the sign function

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But if you put something like x²+y² into geogebra or desmos they can't handle it at all

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How do I resolve this?

hexed bloom
warm wren
#

divide all of them by ABC

hexed bloom
#

ahh gotcha thx <3

burnt zodiac
#

any tips on this would be greatly appreciated thanks just need to know i'm doing the steps correctly

urban pollen
#

cot (-16pi/3) = 1/tan(-16pi/3)
-16pi/3 = -5⅓pi, which means you would go clockwise direction on the cartesian plane to end up in the 2nd quadrant
thus tan (1/3pi) = tan (60°) = sq root 3
and since the angle lies in the second quadrant, tangent is negative so
cot (-16pi/3) = - 1/tan(-16pi/3) = -1/sq rt 3

tepid jungle
#

X is a function of Y, and X is a random walk

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why is Xn independent of Xm- Xn when Xm is just a later step of Xn?

burnt zodiac
#

@tough hatchanova activity

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? it's one way anova acitvity huh

spare spade
#

I need help

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Is anyone online

shadow furnace
#

@spare spade

noble sinew
spare spade
#

2x (2x>2 - 3x -36) Find the coordinates

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Help please

woeful pulsar
rough acorn
#

simple q but idk what rules get to that answer.

tough hatch
#

4=2^2
1/8 = (1/2)^3 = 2^(-3)

rough acorn
#

Ahhhh

#

thx!

rough acorn
#

how dumb am I? sin(45) * 6 = 3 root 2,

that should give the hieght?

gray isle
#

where's sin(45) coming from?

shadow furnace
#

Yeah, where do we get sin(45) from?

proven flare
#

Guys can someone help me

#

I need to understand what this is saying

dull onyx
#

the channel is obviously occupied

proven flare
#

Oh okay

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Where do I ask my question?

dull onyx
#

in a different channel

proven flare
#

Okay

rough acorn
#

NVM

shadow furnace
#

What does AC angles mean?

rough acorn
#

dw, i meant the angles for A and C on the LHS but i messed it up

inner raven
#

(ln(x))^i = a + b*i

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Could someone solve for a and b please?

shadow furnace
#

We can't solve things

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But we could help you solve it yourself

inner raven
#

Basically

#

I was trying to solve for x in cos(x) + i*sin(x) = -ln(x)^i

ionic jewel
#

that's quite a different problem

inner raven
#

And I thought that, assuming that -ln(x)^i was a complex number, maybe finding the real and the immaginary part would have helped me solving the equation

ionic jewel
#

the problem is that ln(x)^i is a function and a+bi is not

inner raven
#

Mhhh yeah you're right

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How could I try solving for x in the starting equation then?

inner raven
ionic jewel
#

hmm well i can go through my thought process, not sure it'll get us anywhere but i don't know the solution off the top of my head

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I'm going to use exponential form for both sides for ease

inner raven
#

Okok, I'd be glad if u try : )

ionic jewel
#

what i was trying didn't end up working

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I'll keep thinking on it

inner raven
#

Ok thank you

#

I'm trying some other ways too but I don't think I'll ever figure it out

ionic jewel
#

$e^{iz} = -\qty(\ln{z})^i$

ocean sealBOT
inner raven
#

Ok so

ionic jewel
#

taking the natural log of both sides might not be terrible actually

#

bring down the exponent and get rid of the e

inner raven
#

You basically reduced cos(x) + isin(x) to e^(xi)?

ionic jewel
#

isn't that right

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or am I super confused rn

#

I'm pretty sure that's right

inner raven
#

That should be right

ionic jewel
#

$iz = i\ln\qty(-ln z)$

ocean sealBOT
ionic jewel
#

divide both sides by i

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$z = ln(-ln z))$

inner raven
#

Ok so

ocean sealBOT
inner raven
#

We took i away

#

And that's so great

ionic jewel
#

raise both to e again while we are at it

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$e^z = -ln(z)$

ocean sealBOT
ionic jewel
#

this sure looks a lot nicer now

inner raven
#

Maybe you should use Lambert function someway

icy sun
#

z < 1?

inner raven
ionic jewel
#

did i miss some restriction?

icy sun
#

Cause ln(z) < 0

inner raven
ionic jewel
#

ah

icy sun
#

Or are we not solving in reals

#

In which case I'll skeddadle cause idk complex logs

inner raven
ionic jewel
#

this has exactly one solution, which is real

inner raven
#

I think we should consider complex solutions as well

inner raven
ionic jewel
#

according to Wolfram at least

#

idk how to solve it

icy sun
#

gasp wolfram?

ionic jewel
#

$e^z + ln(z) = 0$

ocean sealBOT
icy sun
#

Let's see if bounding gets me anywhere

inner raven
#

Thank you all

ionic jewel
inner raven
icy sun
#

Yeah, 1/e < z < 1

#

The algebra is right, 99% sure

ionic jewel
#

,calc 1/e

ocean sealBOT
#

Result:

0.36787944117144
ionic jewel
#

its less than that

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,w e^z = -ln(z)

icy sun
#

Doesn't look it

ionic jewel
#

of course it can't just give the number

ionic jewel
#

0.27

icy sun
#

Hmm

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What did I miss

ionic jewel
#

idk how did you do that

icy sun
#

Oh wait, I'm dumb

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0 < z < 1/e

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hey!

inner raven
#

Shouldn't it be 0 < z < 1/e

icy sun
ionic jewel
inner raven
icy sun
#

I'm not convinced there is an easy solution for this

#

Maybe not even an algebraic one

ionic jewel
#

$e^{e^{i\theta}} + ln(r) + i\theta = 0$

inner raven
#

Maybe we should use calculus someway

ocean sealBOT
inner raven
#

But I have no clue

ionic jewel
#

yeah that's not gonna go anywhere

#

my solution, idk about calculus

icy sun
#

z = 1/z for removing the - if you want

inner raven
thorn kindle
#

it really isn't. try using the taylor series

icy sun
#

I was going to do that after z = 1/z

ionic jewel
#

that's what

icy sun
#

Thanks for stealing my thunder

ionic jewel
#

x^n/n!

#

?

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don't know the Taylor series for log(z)

icy sun
#

same. Was going to google it

ionic jewel
#

$\sum_{n=0}^\infty \frac{x^n}{n!} + \ln(z) = 0$

ocean sealBOT
ionic jewel
#

,w Taylor series ln(z) at z = 0

inner raven
#

This got much more difficult than I thought it was first

icy sun
#

the series depends on where it is centered

icy sun
ionic jewel
#

maclaurin superiority

icy sun
#

It's easy to see where it would roughly intersect, what it looks like etc.

ionic jewel
#

that's still not helpful Mr Wolfram

icy sun
#

But exact values is rip

thorn kindle
#

for re(z)>0, z!= 0

icy sun
#

thanks

ionic jewel
#

uhhh

thorn kindle
#

uhhh

ionic jewel
#

good luck canceling that out with the e^x series

icy sun
#

ahem

#

yeah

thorn kindle
#

you can't have a closed form but you can represent it with an arbitrary amount of precision

ionic jewel
#

so the moral of the story is that we should have just put the original problem into wolfram

inner raven
#

I'm gonna mail blackpenredpen

ionic jewel
#

who

woeful pulsar
#

a youtuber, but why

inner raven
#

I remember he solved something quite similar

woeful pulsar
#

oh, you mean with the W

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Lambert W

ionic jewel
#

really now i actually have to look it up

inner raven
#

Basically in e^(x - a) = ln(x)

icy sun
#

I did

ionic jewel
#

I've seen that function so much and i don't know what it isbwheeze

woeful pulsar
#

it's just the inverse of ze^z

icy sun
#

oh this would be every useful I think

inner raven
inner raven
#

That's useful if you have to figure something like 2^x = x^2

ionic jewel
#

just take the log of both sides works every time

#

if i see any exponent you already know I'm sending in the ln's

thorn kindle
#

that's cheating. you have to equate infinite series of polynomials

ionic jewel
#

don't worry I'll use the series representation of log to do it

steel horizon
woeful pulsar
thorn kindle
#

10 restaurants, n theatres, 4 tourists/restaurant, 6 tourists/theater, 5 restaurants/tourist, 3 theatres/tourist

alpine sable
#

is there any sample paper

#

so that i can pratice

#

i am in 8th grade

thorn kindle
#

practice what

alpine sable
#

questions 🙂

thorn kindle
#

what questions?

alpine sable
#

im literally having the hardest time of my life figuring out why the section i highlighted is true

#

can anyone help?

steel horizon
woeful pulsar
#

to do that start by calculating the number of pairs (restaurant, tourist) such that the tourist visits the restaurant

steel horizon
#

i seee

steel horizon
#

@woeful pulsar any special tip to cover my backlogs ?

woeful pulsar
#

what backlogs?

woeful pulsar
woeful pulsar
alpine sable
steel horizon
alpine sable
#

do the equations look similar? is there a way to convert this to the one i sent in that pic?

#

idk ughhh mine looks messy

woeful pulsar
#

did you do something like (y-k)=m(x-h)

#

oh wait

#

i see it has to pass by h, k

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and (h, k) is not necessarily a point on the graph

woeful pulsar
alpine sable
#

ignore this one, its useless lol

quaint pond
#

hello, could someone help me understand the solution to this problem:

#

the answer apparently is

alpine sable
woeful pulsar
#

because I thought the point of tangency was (h, k)

woeful pulsar
# quaint pond

use stars and bars, 5 stars 5 bars.
1|2|3|4|5|6
where the star is gives the number

alpine sable
#

which is apparently the same equation as the one in the image

#

how do i reduce it to a second power equation? it doesnt look clean at all

quaint pond
#

what would that represent

languid moat
#

I'm a beginner what topic should I start first?

woeful pulsar
languid moat
#

idk I want to rebuild my math foundation so where should I start

woeful pulsar
#

it's free, easy and you can do it anytime

languid moat
#

i have this book called "basic mathematics by serge lang" should i complete it

#

it starts with addition up to functions should i read it, it seems simple but it might help rebuild my foundations

woeful pulsar
#

i think khanacademy is decent too since it gives practice problems

yeah you can try reading it and see how it goes for you

languid moat
#

yep I think I should read it, I really want to have a strong foundation so it would be easier to learn harder topics

#

I hope I can participate here in the future

full igloo
#

how do i find x here?

woeful pulsar
#

this channel is really crowded lol

#

check timestamps

woeful pulsar
tight locust
#

all you need is arc AB

woeful pulsar
#

hmm lemme check

#

yeah all the information is there

#

consider triangle ABE

tight locust
#

x = 40 degrees

tight locust
woeful pulsar
#

ensure you engage the question asker

urban pollen
#

angle abc is 90 degrees cause of right angle in semicircle

#

then angle bad is 50° cause angle in centre = 2 angles at the circumference

full igloo
#

ah

urban pollen
#

then looking at triangle abe angle aeb is 40°

full igloo
#

bad=50 already found that

#

but i stuck after that..

urban pollen
#

ah

full igloo
#

ah

urban pollen
#

then focus on only triangle ABE

#

180° - 90° - 50° = 40°

full igloo
#

ah so its 40°?

#

thank you :D

urban pollen
#

yepp

#

welc :))

full igloo
#

might eventually ask more

urban pollen
#

i'll try my best HAHA

tight locust
#

(130-50)/2

full igloo
#

noted

#

stuck again :(

woeful pulsar
full igloo
#

BDC and CAD

woeful pulsar
full igloo
#

what do you mean?

#

i cant understand that well..

woeful pulsar
#

these angles are the same size

full igloo
#

BDC is 60°?

#

how about CAD? is it any different?

woeful pulsar
full igloo
#

ah but i cant seem to find it

is there any way to find it?

#

i got BDC now so thats not a problem

woeful pulsar
#

how did you get BDC

full igloo
#

both are on Arc BC apparently

#

BAC=60 so i suppose BDC=60

woeful pulsar
full igloo
#

wait i found it :O

stable orbit
#

Q11 quadratic equations

#

Assignment

gray isle
#

what have you tried?

hallow flax
#

I would suggest, to start by writing down the conditions you have in mathematical terms, so to extract all information from the problem, then, the problem might be easier.

woeful pulsar
#

model the question with an equation

urban pollen
#

let the number of students be x and the number of apples distributed to them be a, 300/x = a and 300/x+10 = a - 1

#

x = 50

woeful pulsar
#

also don't just give answers

#

engage the person who asked the question

woven plaza
#

n= 300/x
n-1=300/x+10
Where x is number of students and n is number of apple each student gets in first case

#

Solve for x

urban pollen
#

oh wait yaaa thats a shorter method ah sorry

woven plaza
solid lintel
#

Wait I'll send it

woven plaza
#

If you have a fixed goal then you can start with basic equations and transform them into whatever curve you want

woven plaza
#

Yeah that's a semi circle

jagged imp
solid lintel
#

Just straight lines and semi circles and ellipses

woeful pulsar
#

well it's possible as a piecewise defined function that is noncontinuous

solid lintel
woven plaza
#

The eyes will be circle of radius same as the "b" of elliptical equation

woeful pulsar
#

of course you'll need to use a parametric equation probably

solid lintel
#

See I had this idea

woeful pulsar
#

oh wait batman curve

woven plaza
#

Have you drawn the rectangle and hands?

solid lintel
#

I could add (1-|sign(f(x)|)(1-sign(y)) to the entire equation

woeful pulsar
#

yeah we can also use a f(x, y)=0 equation

#

that too

woven plaza
#

It seems hands are at 45° so hands are simply shifted formof y=x and y=-x lines

woeful pulsar
#

but maybe find equations for each of the parts first

woven plaza
solid lintel
solid lintel
solid lintel
solid lintel
#

But geogebra hates it

solid lintel
proven flare
#

Hey guys I have a few questions about summation

#

Can you guys help me understand these or give me resources to help me

split slate
#

How might I find x?

#

I don't even know where to begin with this

alpine sable
#

You could use Sine rule

#

If you haven't learnt that yet you could just use your trig ratios for right angular triangles

split slate
#

What's the sine rule?

#

But considering I don't know what that is...

#

The other option seems more viable

split slate
#

Like?

#

Find the length of the dotted line

alpine sable
#

yeah and then use that to find x

split slate
#

Oh ok

#

Thanks!

ocean sealBOT
#

Πολλά άτομα είναι

split slate
#

Yeah...

#

I'll look into it later

#

very late at night

alpine sable
#

and to solve for side lengths just get the reciprocate of that

pallid sail
#

there isn't much to look into

#

you got the sides and the angles

#

you just need to utilize the formula that was given to you

alpine sable
#

hey, check out this competition

#

A car traveling at 53 km/h hits a bridge abutment. A passenger in the car moves forward a distance of 65 cm (with respect to the road) while being brought to rest by an inflated air bag. What force (assumed constant) acts on the passenger’s upper torso, which has a mass of 39 kg?

#

Why do we care about the average velocity here? I meant (53 + 0)/2 km/h, and we find the acceleration using the average velocity..?

#

We could just use v_f^2 - v_i^ = 2ad, where v_f = 0 and v_i = 53 km/h (but converted to meters/sec)

#

To find the acceleration?

vale wigeon
#

we care about velocity to find the change in kinetic energy, which gives us the work done by the stopping force

#

we don't know how long the passenger took to be brought to a stop nor do we need to

#

@alpine sable

alpine sable
#

We use v_f^2 - vi^2 = 2ad to find the acceleration when the car was stopping

vale wigeon
#

hm wait

#

i think you will have the same result either way

#

ah yes

#

yes you will

alpine sable
#

No I got 6500 N

glass lichen
#

as opposed to...?

alpine sable
#

6600 N

glass lichen
#

Yeah... both kinematics and energy give ~-6502N

#

so likely a typo

#

im assuming you got the 6600N from the answer key

alpine sable
#

I got like 6474 or something

#

Not 6502

#

But I rounded up to 2 sigfiggs

#

53 km/hr is 14.7m/s. The average speed while decelerating is vav = 7.4m/s. The time of deceleration is t = x/vav = (0.65m)/(7.4m/s) = 8.8×10−2 s. The deceleration is a = ∆v/t = (−14.7 m/s)/(8.8×10−2 s) = −17×102m/s2. The force is F = ma = (39kg)(1.7×102m/s2) = 6600 N.

#

This is the solution's manual solution

glass lichen
#

$a=\frac{v_f^2-v_i^2}{2d}=\frac{-(\frac{53}{3.6})^2}{2(\frac{65}{100})}\approx -166.73$

ocean sealBOT
alpine sable
#

,w 0^2 - (53 * 10/36)^2 = 2 * a * (0.65)

alpine sable
#

,w 167 * 39

alpine sable
#

That's not 6502 though

#

,w 166 * 39

glass lichen
#

yeah cause you rounded in an intermediate step

alpine sable
#

What intermediate step?

glass lichen
#

You used a=167 and a=166

#

that's rounded

alpine sable
#

What else should it be?

#

We only care about two sig figs?

glass lichen
#

use the actual value....

#

you round at the end

alpine sable
#

,w 166.726 * 39

alpine sable
#

Okay thanks I didn't realize I shouldn't round like that

glass lichen
#

,w (-(53/3.6)^2/(2*0.65))*39

alpine sable
#

But still look at the solution above by the solution's manual

#

It's way different

#

,w 39 * (1.7 * 10^(2))

glass lichen
#

yeah they used average stuff

alpine sable
#

Okay but only one of these can be correct?

glass lichen
#

catshrug ask your teacher

alpine sable
#

It's from a book

#

How was the a = F/m calculated?

#

,w (4.5 * 10^(-16))/(9.11 * 10^(-31))

alpine sable
#

It should be 4.9 * 10^14??? Or am I missing something?

#

But the solution's manual also says 4.9 * 10^15, so I am confused?

glass lichen
alpine sable
#

Two typos (same!!!) in two different sources I guess

#

I'm shooketh

mint rock
#

Doing some crypto analytics and have arrived at something of the form A^x -Bx = C. Is this algebraically solvable?

#

Quick search says that it is not, but then I do not know how to approximate it either.

quaint trout
#

What is the exact question given to you?

#

There is no such thing as cross product in R^5

sudden crypt
#

well not with 2 input vectors, it is defined for 4 input vectors

quaint trout
#

No, if the question is "Find the cross product of a and b" and this is a and b

#

There is no answer

#

That's not a thing

#

You can't do anything

sudden crypt
#

the dot product however is defined, maybe you swapped the terms?

quaint trout
#

So is the question you were given to find the cross product or to do something else and you wanted to try to do it using a cross product?

#

Can you send a picture?

#

Oh, it's probably a trick question

#

You are supposed to say it's not defined

#

Or something

#

👍

alpine sable
#

q 21

#

can someone have a look

#

im strugglin so bad TT

gusty ravine
#

yea the middle part is right

#

after u arrange the middle part you're gonna be left with 1 vowel and 5 consonants, so u just need to permute these 6 in the other spots @alpine sable

alpine sable
#

i don't get why

gusty ravine
#

i dont see why its not 4! * 6!

opaque zodiac
#

: Construct a matrix that triples the height, width, and length of an objective in 3D. What exactly this question wants ?

torn lion
ocean sealBOT
#

Nonassociative Semigroupoid ✓

opaque zodiac
#

im doing this on programming maths so this is actually maths right ?

torn lion
#

I don't know what programming maths is, but it looks like a fairly standard linear algebra problem to me.

opaque zodiac
#

is this like theory thing ?

#

it seems simple thats why i ask

torn lion
#

You don't need to prove anything, if that's what you mean by "theory thing". You just need to find the matrix.

opaque zodiac
#

i thought of it, but thought was too simple asnwer

#

ah

torn lion
#

It is a rather simple problem.

alpine sable
#

Any idea on this sum?

torn lion
#

So basically $S=\sum_{1}^{n}(3i^{2}-i)$, right?

ocean sealBOT
#

Nonassociative Semigroupoid ✓

alpine sable
#

yes

torn lion
#

Do you know $\sum_{1}^{n}i$ and $\sum_{1}^{n}i^{2}$?

ocean sealBOT
#

Nonassociative Semigroupoid ✓

torn lion
#

They're pretty standard identities

alpine sable
#

n(n+1)/2 and [n(n+1)(2n+1)]/6

torn lion
#

Combine that with the fact that $\sum(f(i)+g(i))=\sum f(i)+\sum g(i)$ and $\sum af(i)=a\sum f(i)$, where $f,g$ are functions of $i$ and $a$ is some constant, and you should be good.

ocean sealBOT
#

Nonassociative Semigroupoid ✓

alpine sable
#

Alright

#

Thank you

torn lion
#

That is, you can say $S=\sum_{1}^{n}3i^{2}-\sum_{1}^{n} i$, etc.

ocean sealBOT
#

Nonassociative Semigroupoid ✓

opaque zodiac
alpine sable
#

I understood

alpine sable
#

I do not do math on a purpose now ,I just like it but I had no idea on this one ..

opaque zodiac
torn lion
glass lichen
#

I, yes

torn lion
#

But it's basically the answer that Mosh gave.

glass lichen
#

$T[v]=3v\implies [T]_B^B=3I$ for canonical basis B

ocean sealBOT
torn lion
alpine sable
#

What’s 17 + 204871773874

#

I know this can be solved with the quadratic formula but because the formula is beyond the curriculum of the present chapter is there any other way to solve it?

glass lichen
torn lion
alpine sable
#

Like 6 or something thanks anyway

alpine sable
#

Wha

#

Sorry

glass lichen
#

@alpine sable you need the quadratic to not have roots.. what does that make the discriminant

torn lion
opaque zodiac
glass lichen
#

It's find matrix representation based on the mappings that were pointed out

alpine sable
#

D = b^2 - 4ac

#

If D is bigger than 0 then the thing has real roots

torn lion
glass lichen
#

We love people that ignore what you say sully

glass lichen
#

yes, so solve b^2-4ac<0

opaque zodiac
torn lion
alpine sable
#

Yeah I mean

#

I know how can I do that

#

But the thing is

#

That thing is beyond the current chapter

tawdry saffron
#

how to calculate the maximum value of x+y of a circle equation

torn lion
#

In that case it will probably just be the computation that I had mentioned in the beginning.

opaque zodiac
alpine sable
#

There must be alternative

#

Fivht

#

Right*

torn lion
#

I mean, what techniques did you learn in the chapter?

tawdry saffron
#

if (equation) what is the maximum value of x+y

#

how to start with such a question?

torn lion
tawdry saffron
#

oh sorry

torn lion
#

Looks like 9 opened recently too

alpine sable
#

I mean

#

None which seem helpful

#

Just some stuff about polynomials

torn lion
#

What stuff about polynomials did you learn?

alpine sable
#

Basic stuff

#

A summary which is supposed to carry outside the syllabus stuff

torn lion
#

Honestly I'd just use the discriminant.

alpine sable
#

Vieta's formula too

#

If that has anything to do with this

alpine sable
torn lion
alpine sable
#

Alpha + Beta = -b/a
Alpha * Beta = c/a

#

And for cubic polynomials too

torn lion
#

Okay, so that provides something.

alpine sable
#

I tried writing it that way

#

But cut it down

#

Because roots are supposedly unknown, and it says any x so no clue

torn lion
#

If we have no real roots, i.e. $\alpha$ and $\beta$ are complex, what does that tell us about $-b/a$ and $c/a$?

ocean sealBOT
#

Nonassociative Semigroupoid ✓

alpine sable
#

Complex numbers are outside the scope of my entire curriculum

torn lion
alpine sable
#

But this got nothing to do with them ig

torn lion
#

Use the discriminant. Write a page explaining why the discriminant works if need be.

alpine sable
torn lion
#

Honestly fuck it, your teacher should be happy that you're taking initiative and reading ahead to the next chapter anyway, and a right answer is a right answer regardless of how you got there.

alpine sable
#

I don't have a teacher lmao I mean our school book has questions like

Find the roots of
x^2 + 2x + 1

#

Thanks

torn lion
#

Who grades the answers to the questions?

#

And gives lectures, etc.?

alpine sable
#

These questions are from a coaching institute or smth and I don't take coaching + school holidays are going on and our teacher doesn't like doubts with questions sadly

fair crater
#

That's a really weird teacher...

torn lion
#

Honestly a right answer is a right answer is just what I have to say to that.

fair crater
#

Generally teachers like engaged students

torn lion
#

As long as how you got there is valid, of course.

glass lichen
#

Im confused how, if you havent learned quadratic theory in any capacity, why are you doing quadratics/being told to do them

alpine sable
#

I haven't been told by anyone to do these questions I have already completed the school textbook and am using this booklet to do questions

torn lion
#

I'm confused why you're learning about general polynomials before learning about quadratics. I learned about polynomials as a generalization of quadratics when I was in highschool.

glass lichen
#

So you're opting to do questions you have no fucking clue how any of it works?

alpine sable
#

I know quadratics

glass lichen
#

you said you didnt

alpine sable
#

I already mentioned it

#

That I do

torn lion
#

Then you have the answer.

glass lichen
#

then what was the problem of "not being at the quadratics chapter" yet?

alpine sable
#

I expected an explanation without using that equation

glass lichen
#

You asked a question about a quadratic...

alpine sable
#

Isn't a quadratic polynomial still a polynomial

glass lichen
#

yes

alpine sable
#

Then?

glass lichen
#

then what?

#

it'a a quadratic, so all the quadratic theory tricks come into play

fair crater
#

@alpine sable Without you listing the 'acceptable methods' it will be difficult for us to comment on the appropriateness on use of methods

alpine sable
#

I already listed them tho

fair crater
#

You would essentially be asking strangers to deduce your syllabus which is like, magic on top of magic

alpine sable
#

There's just one

fair crater
#

I think you just said 'no quadratic formula'?

alpine sable
#

Vieta's thing

glass lichen
#

something like factor theorem / remainder theorem, or generalized Vieta's arent usually used in quadratics

fair crater
#

😐 listing no goes makes it hard to know the 'ok-to-go'?

alpine sable
#

Why are you guys all on me sully

glass lichen
#

cause you're really not making much sense

alpine sable
#

Idk

glass lichen
#

it's a quadratic, so use stuff for quadratics

#

if it were a cubic, then use stuff for cubics

alpine sable
#

Bro

#

Forgive me

torn lion
alpine sable
fathom matrix
#

dam

alpine sable
#

Ok so I solved that, and like I get

(K-4)(K-2) but the answer key says 3 sully

#

No clue why

indigo jetty
#

i think this question is not worded properly

#

if it asked for K as an integer then the answer is 3

alpine sable
#

Is it talking about the net force $\sum F_x = F_{m2} - F_{m2m1}$ having acceleration $2.6 m/s^2$ or just $F_{m2}$?

ocean sealBOT
lunar relic
#

My friend and I are conflicted on whether or not it's possible to trivially integrate this integral. He says to treat y like a constant and integrate it, but then differentiating it, I get something different than what we start with.

alpine sable
lunar relic
alpine sable
#

okay?

#

I'm not sure what you're expecting here

#

You treat it as a constant when you integrate, but not when you differentiate

#

Why would you expect the answers to be the same?

#

@lunar relic

lunar relic
# alpine sable You treat it as a constant when you integrate, but not when you differentiate

yeah, my question is can you even treat y as a constant when integrating? If not, how would you integrate this?

I don't know if my friend's assumption is correct, which is just integrate without touching y. What I'm trying to show is that if we say y is constant, integrate it, then take the derivative, since y is a function of x, it doesn't give the same thing back because of the dy/dx. If I take the partial derivative, then y can be assumed to be a constant since we're simplifying the problem.

alpine sable
#

It does give back the exact same thing

#

y is constant, so dy/dx = 0

lunar relic
#

Oh huh

alpine sable
#

Either y is or isn't constant

#

it can't be both

#

You can integrate it once more if you need to

#

Where you treat x as constant

#

Anyway, in your example, assuming y is a function that does not depend on x, it would still be the correct answer

lunar relic
alpine sable
#

Okay so then you can't treat it as a constant

lunar relic
#

so in that case guess my friend and I are back to step 0 on integrating this lol

alpine sable
#

You also can't integrate arbitrarily abstract things

#

Like you can't say ∫ x f(x) dx = x^2/2 f(x) + C

#

And pretend f(x) is constant

#

That doesn't make sense

#

You need to know what y is to integrate it

#

That being said

#

You can always use integration by parts on problems like this, usually.

lunar relic
#

actually wait let me think about this

alpine sable
#

Perhaps the correct answer is in the form of integration by parts.

safe kite
#

need some one to walk me through how to work this voice explaination would help alot

full cypress
#

anyone know any websites where i can practice algebra?

topaz scaffold
#

Wolfram Alpha?

topaz scaffold
#

Regular algebra

#

Idk what's the name

full cypress
#

regular

full cypress
topaz scaffold
#

Oh

#

Khan academy ig

#

Or Wolfram

#

Depending on what kind of questions you want

full cypress
#

imma check out wolfram

#

it has hard questions right?

topaz scaffold
#

I only know that it has questions

#

I've never tried the algebra ones tho

full cypress
#

ight thanks

gentle turtle
#

Please correct my solution..
Why my solution different from calculator -4x+1/3x-2

ionic jewel
#

,w inverse (2x-1)/(3x+4)

ionic jewel
#

oh you forgot to change the y on the bottom to an x but idk if that's just your handwriting

scenic crystal
#

I want to get sum of the squares of the first ten natural numbers like = 1^2 + 2^2 + 3 ^ 2 .....10^2 = 385, Is there any formula to do this?

ionic jewel
ocean sealBOT
ionic jewel
#

oh there's also a closed form let me find it

#

,w sum from n = a to b of n^2

ionic jewel
#

-1/6 (-1 + a - b) (-a + 2 a^2 + b + 2 a b + 2 b^2)

#

with a as the lower bound, and b as the upper bound

#

in your case a = 1, b = 10

scenic crystal
ionic jewel
#

you can of course simplify that if you always want to start at a = 1 or something

#

yw

ionic jewel
#

yw

dawn galleon
dawn galleon
#

<@&286206848099549185>

viscid cove
#

have you plotted them in the graph?

alpine sable
#

For this problem, why can you not use the power rule for y^2? Why did the instructor use the chain rule?

dawn galleon
#

bruh go to another channel

#

channel in use

lapis valley
#

d(y^2)/dx = d(y^2)/dy * dy/dx = 2y* dy/dx

alpine sable
#

Ty

alpine sable
viscid cove
#

come on guys, rules..

alpine sable
#

Tried a lot of ressources, but yet don't understand integrals as much, can somebody help me get a clean understanding?

viscid cove
#

next channel pls

ionic jewel
#

area under a curve between the bounds

alpine sable
ionic jewel
#

well unfortunately I'm not available to teach the entirely of integral calculus

viscid cove
#

@dawn galleon i might have the answer, you need to cross check it though

alpine sable
#

I just need the main concept of integrating, not all of it lol

#

An explanation of what it is

#

Basically

viscid cove
#

jesus there's literally a general channel

#

so, the period is 365, cause seasons repeat in a year

dawn galleon
viscid cove
#

its a little rough due to the given data but its follows a sine curve

ionic jewel
ocean sealBOT
viscid cove
#

yeah yeah

ionic jewel
#

I found that starting by learning Reimann sums helped nicely so maybe those those up too

viscid cove
#

we have the period=365, ratio= sine, amplitude=....

alpine sable
#

Alrighr

viscid cove
#

(highest temp-lowest temp)=19--8=27

#

and yeah the midline and shift, one sec

dawn galleon
viscid cove
#

there's a stat aspect to it so find the mean value and the median

dawn galleon
#

Period is 365?

viscid cove
#

uh huh

#

well the midline passes though one of them, if the given data is symmetric both median and mean will be the same( i think)

primal ether
#

the data doesn't seem symmetrical about the middle

viscid cove
#

it must be symmetric about some line

primal ether
#

if the range is 27 the coefficient of sin should be 13.5 right?

dawn galleon
#

what should the amplitude be?

primal ether
#

and adjust the constant to fit

viscid cove
#

13.5

primal ether
#

this is the best i've gotten

dawn galleon
primal ether
#

as the amplitude is 13.5, and we know that there is a peak at temp 19

#

we can use the fact that a sin x + b has a peak of a+b

dawn galleon
#

did u use the equation Asin(b(x + c) + d,

primal ether
#

woops

#

13.5sin(x-100)+5 is what i got lol

dawn galleon
primal ether
#

The sine graph has a period of 360 degrees

#

We can disregard the period as 360 is close enough to 365

dawn galleon
#

Ohh can u send the link of ur desmos graph

primal ether
#

The last 2 points don't align

dawn galleon
#

thanks

viscid cove
#

But if he was supposed to do stat operations for the means and such, wouldnt the approximation be too much?

#

yours is still better though, i suppose its fine

primal ether
#

the data isn't

#

the best

viscid cove
#

the last two points are a bitch

#

$$y=13.5\sin\left(\frac{\pi}{182.5}\left(X-106.5\right)\right)+5.833$$

ocean sealBOT
#

drunkzurg

viscid cove
#

100 is still too much imo, you cant explain where it came from

primal ether
#

good approx

#

no sine graph can satisfy the last 5 points though

viscid cove
#

amplitude: (max-min)/2, period: 365 because seasons repeat, x translation 106.5 because the minimum point is in 15 and each quarter of the period is 365/4=91.25 and the y translation is comes from (max+min/2)

#

true

feral iron
#

Does any1 see a formula to make column A match column B from 0-359°?

viscid cove
#

match?

#

why would you want that?

feral iron
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Not match, but match the relationship in the spreadsheet, so when the ship angle is 90°, the camera angle should be 0°

viscid cove
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no no i dont think its anything like that

feral iron
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It is something like (Ship angle - 45)x2

viscid cove
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i might be wrong, could you send the actual question or language associated with it?

feral iron
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Its my own question - ship always needs to face up in camera view (top down). I have tested all of the above values and they work, but I dont know how to make it work for increments bettween the values

viscid topaz
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Bruh, (ship angle + 360 - camera angle ) % 360 = 90

feral iron
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The camera angle needs to be set via a formula, depending on ship angle rather than manually entered

viscid topaz
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Same deal, just rearrange the formula to solve for camera angle, right?

feral iron
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Correct