#help-27

1 messages · Page 134 of 1

spice linden
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and If yes how would I prove this?

rich summit
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Decreasing doesn't necessarily mean the limit is 0

spice linden
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how do I check if it's bounded

spice linden
rich summit
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1, 1 - 1/4, 1 - 1/4 - 1/8, 1 - 1/4 - 1/8 - 1/16 is also decreasing, but doesn't converge to 0

spice linden
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?

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I think you calculated the first terms incorrectly

rich summit
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no, this is another sequence to demonstrate the principle

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Have you proven a_n is decreasing btw?

spice linden
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no

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that's what I'm asking

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how do I prove it

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i can see that it is decreasing

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but I don't know how to prove it

wooden veldt
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This is fine you just need it to be eventually decreasing

spice linden
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but how do I prove it though

wooden veldt
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Induction

spice linden
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ahh ok

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lemme try it

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but

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what would I use as my induction basis?

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i thought I have to use the smallest/first term

spice linden
rich summit
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You can start anywhere with your induction basis, but you will only prove it's decreasing for numbers larger than your induction basis

spice linden
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which is all I need

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dope

wooden veldt
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Yeah when doing your induction you will probably need n to be bigger than something

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So your base case will whatever that is +1

spice linden
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it would be for n>3

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the decreasing pattern holds from the 3 term onwards

rich summit
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Yeah, so for the inductive step assume that a_(n + 2) < a_(n + 1) < a_n

spice linden
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wait nvm

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its just the two steps in one

rich summit
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yeah, this way you can do induction in one go, otherwise there might things like odd and even separately

spice linden
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ok i'm working on it

spice linden
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where do I go from here? have I done something wrong?

rich summit
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The trick is to rewrite the recursion this way $$a_{n+2}<\frac{1}{3}a_{n}+\frac{1}{2}a_{n}$$

woven radishBOT
spice linden
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$$a_{n+2}<\frac{1}{3}a_{n}+\frac{1}{2}a_{n-1}$$

woven radishBOT
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AzerimA

rich summit
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You leave the 1/2a_n unchanged

spice linden
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oh

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is it because we know that a_n is larger than a_n+1 so if we replace it with something bigger the equation still holds?

rich summit
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Yeah, a_n > a_n+1

spice linden
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and that's valid cuz it's our induction assumption right?

rich summit
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Yeah, I think the best way is to do strong induction actually and assume the sequence is decreasing up to a_(n+2)

rich summit
spice linden
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what is strong induction?

rich summit
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You assume the inductive hypothesis is true for all k <= n and then prove it will also be true for n + 1

spice linden
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is this the only difference?

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and we can just assume that?

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no problem?

rich summit
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Yeah, well N_0 <= k <= n at least

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where you started at N_0 with your induction basis

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but in this case assuming the previous 2 values also works

spice linden
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my N_0 is 3 in my case

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but it doesn't tho

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a_3 is larger than a_2

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and a_2 is larger than a_1 and it is larger than a_0

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wait nvm

rich summit
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just assume the previous 2 values, that's easier

spice linden
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a_0 < a_1 and a_1 > a_2 and a_3 > a_2

spice linden
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u mean a_0 and a_1?

rich summit
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assume it's true for a_n and a_n+1, then it will be true for a_n+2, but also still for a_n+1

spice linden
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I don't understand what you mean by that

rich summit
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You know it's true for a_n and a_n+1, then you want to prove it's also true for a_n+1 and a_n+2, you keep shifting them a place

spice linden
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yes

rich summit
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I just noticed that my way only proves a_n+2 < a_n for all n, not a_n+1 < a_n, sorry

spice linden
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bro I don't even understand the problem u r dealing with rn

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that's bad

rich summit
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I think you have to do induction on 2 bounds at the same time

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I suspect you can prove a_n+1 > 0 and a_n+1 < 5/6a_n or something like that

spice linden
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what does that mean

spice linden
rich summit
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You can open a new channel if you want tomorrow, hopefully somebody else can help

spice linden
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if you found out how it is supposed to be solved, drop me a dm

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if u end up working on it

rich summit
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yeah

spice linden
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ok thanks for your time bro

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gn

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!close

rich summit
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humble fractal
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Can someone help me with part b please?

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humble fractal
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<@&286206848099549185>

dense jay
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whats up?

humble fractal
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I got stuck on part b

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Can you help me please?
@dense jay

dense jay
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have you drawn a diagram of some kind for the scenario?

humble fractal
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yeah

dense jay
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may i see

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try take a pivot at c

humble fractal
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my calculation and my diagram

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@dense jay

dense jay
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you didnt multiply Td by its distance from c

humble fractal
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oh okay I see

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Can I dm to ask some maths question please, if you think that is okay

dense jay
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i dont do dm

humble fractal
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oh okay

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@dense jay

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Thank you

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heady coral
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Hi, I'm trying to understand this proof. My question is: If I'm using contraposition, how should I write the statement? For example, if 'x' is a negative number and 'n' is an even number, then 'x^n' is a negative number, the contraposition will be: if x^n is not a negative number, then x is not a negative number or n is not an even number

upper schooner
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Well just "plainly", it'd be "if there isn't at least one box with at least ceil{N/k} objects, then there aren't N objects in the k boxes"

heady coral
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:(

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Is there another form to show it? contraposition is weird :((

upper schooner
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It can be a bit weird at times NervousSweat you could e.g. phrase this one as a proof by contradiction, which basically does the exact same thing

patent marsh
upper schooner
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In fact, the proof is pretty much identical

heady coral
upper schooner
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sadStitchCry you're not happy with proof by contradiction?

heady coral
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Yes, but if is similar to the other then I still without understand it

upper schooner
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Well basically for by contradiction, you'd assume that N objects are in the k boxes, but that you don't have at least one box that has ceil{N/k} objects

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Everything they said basically then gets you to that within the k boxes, you must have less than N objects

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But that contradicts what they've shown

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It is a bit annoying here in this case negating the statements bcaForgiveBeg3

heady coral
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Why I'm adding and resting the one in the yellow part?, and the light blue part is definition of ceil function?, how that inequality shows me that I have less N objects? I still without understand why that is a contradiction pandaOhNo

upper schooner
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For the blue part, if N/k is an integer then you know that ceil{N/k} = N/k, and that’s strictly less than (N/k) + 1

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If N/k is not an integer then you know that because ceil{N/k} is the next integer greater than N/k, you have ceil{N/k} - N/k < 1 (because the distance between any two integers is at most 1)

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You’ve basically assumed that no boxes have at least ceil{N/k} objects, so all boxes must have less than ceil{N/k} objects, and cause the quantity of objects is integer you then would need to have ceil{N/k} - 1 objects or less

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The “largest” possibility is that all of those k boxes have the ceil{N/k} - 1 objects, which is how they get this:

upper schooner
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They then basically replace the ceil{N/k} with the blue part you’ve mentioned, which is how the yellow ends up appearing

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If any of that makes it clear? (I’m assuming not bcaForgiveBeg3)

heady coral
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I'm reading, english is not my native language blobsweat

upper schooner
heady coral
upper schooner
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Excuse the bad drawing, on mobile NervousSweat

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But like say N/k isn’t an integer, then the ceiling is you rounding it up

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But that green distance has to be less than 1, otherwise you’d be able to find another integer that would be closer to N/k

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If that makes it any clearer?

heady coral
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pandaHugg yay! yes I understand it :D

upper schooner
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yayy perfect AntlerLove

heady coral
upper schooner
heady coral
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yes yes, sorry for being slow

upper schooner
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It happens LanLove don’t be sorry, we’re all here to help you! SChug

heady coral
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So I get that my total number of objects is < than my N objects, and that is the contradiction?

upper schooner
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But that’s impossible Hehe

heady coral
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Oooh

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I understand!!!!!!!!!!!!

upper schooner
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SCCOZY perfect

heady coral
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thank you so much <<<333

upper schooner
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Always a pleasure to help you LoveYou

heady coral
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raven swift
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let P be a polynomial fuction and p(x)=x^4-mx^3+4x^2-6x+8 if (x-2) is a factor what is value of m?
help?

tribal sierra
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what have u tried

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if x-2 is a factor what do u know about p(x)

crisp niche
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then due to Bezout Theorem P(2) = 0

raven swift
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and get 28-8m=0

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solve for m?

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which is 7/2

tribal sierra
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yes

raven swift
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do i write -7/2

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or pos 7/2

tribal sierra
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7/2

raven swift
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would the negatives cancel out

tribal sierra
raven swift
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and it would be plus?

tribal sierra
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wat

raven swift
crisp niche
tribal sierra
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just replace m with 7/2

raven swift
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it would be -(-7/2)

tribal sierra
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if its -m its -7/2

raven swift
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which is 7/2

raven swift
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or neg 7/2

tribal sierra
tribal sierra
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so m = 7/2

crisp niche
raven swift
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would it be -(-7/2)

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which is +7/2

tribal sierra
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yes

raven swift
tribal sierra
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idk factor theorem ?

crisp niche
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In algebra, the polynomial remainder theorem or little Bézout's theorem

raven swift
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tribal sierra
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trail trench
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jaunty mantle
#

What’s the definition of a factorial?

trail trench
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idk but this was the answer \

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i dont know how it got that

jaunty mantle
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Well how can you simplify something if you don’t know what it means

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What does ! Mean

trail trench
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idk how to explain it with a variable but i know 5! is 1 * 2 * 3 * 4 * 5

tribal sierra
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write (2n+1)! in terms of (2n)! * something

trail trench
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like replace n with a number?

jaunty mantle
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So what would (n)! Mean

trail trench
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idk i guess n * n ?

tribal sierra
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is 5! = 5 * 4 * 3 * 2 * 1

trail trench
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im lost cause ive never done a factorial with a variabl;e

tribal sierra
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n! = ?

jaunty mantle
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What’s 3!

trail trench
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123

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oops

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1 * 2 * 3

jaunty mantle
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What’s 4!

trail trench
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1 * 2 * 3 * 4

jaunty mantle
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What’s 10!

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Let me answer this

trail trench
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lmao

jaunty mantle
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I would say 1 * 2 * 3 * … * 9 * 10

trail trench
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mhm

jaunty mantle
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(There’s a reason)

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Now what would n! be?

trail trench
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i have no clue im so lost

jaunty mantle
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Or perhaps what would 20! Look like?

jaunty mantle
trail trench
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n * n *n ... n ?

jaunty mantle
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Try 20! First

trail trench
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like write it out or simplify it

tribal sierra
jaunty mantle
trail trench
tribal sierra
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it would be

jaunty mantle
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Let’s try 20! First

tribal sierra
trail trench
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oh ok

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um ok

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so

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1 * 2 * 3 ... 19 * 20

jaunty mantle
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What about 25!

trail trench
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1 * 2 * 3 ... 24 * 25

jaunty mantle
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So a cool thing you might notice is you always start with 1, 2, 3, etc

trail trench
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mhm?

jaunty mantle
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(Unless you’re asked 2! In which case it ends at 1 * 2)

trail trench
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mhm

jaunty mantle
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So in general we might want to say

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n! = 1 * 2 * 3 * … * (n-1) * n

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Does that make sense?

trail trench
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why is it n -1

jaunty mantle
trail trench
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oh ok

jaunty mantle
trail trench
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i get it

jaunty mantle
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Yeah right

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So what would (n+1)! Look like?

trail trench
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so n is the final number

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um

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(n-1) * n * (n+1) ?

jaunty mantle
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With the 1 * 2 * 3 * … at the front

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Now we might notice the first n terms just make n!

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So then (n+1)! = n! * (n+1)

trail trench
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they ar ethe same?

jaunty mantle
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Well (n+1)! = 1 * 2 * 3 * … * (n-1) * n * (n+1)

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Do you agree?

trail trench
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yeah

jaunty mantle
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Well that first part is just n!

trail trench
jaunty mantle
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Yep!

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All you needed was to know what the ! Meant

trail trench
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okok i get it now

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yeah i see ok thanks

#

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royal laurel
devout snowBOT
royal laurel
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So the teacher was trying to find the solution of x^3=1

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Yet, it so singular that it seems like he forecasted the solution

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I mean how does he knew k=1,2 are the solutions?

royal laurel
crisp niche
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so cube root is a set consisted of three elements

royal laurel
crisp niche
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yes, we start from k = 0

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so if we have three elements, you write

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k=0, k = 1, k = 2

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you use , of course, the formula for elements of nht-root, that can be also derived fm de Moivre theoerm but to compute, you may use ready formula

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it can also be interpreted as the vertices n of a regular polygon that lie on a circle with a radius equal to the arithmetic root n of this degree

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so if oyu have cube root, you take 360 degrees and you divide by 3, so roots lie on 0, 120, 240, degress

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i just simpklify my explanaiton

crisp niche
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to have all angles equal

royal laurel
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Is there any property of nth-root that attributes to this phenomenon

crisp niche
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i wouild start explanations from de Moivre theorem, do you know it ?

royal laurel
royal laurel
crisp niche
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then if you replace n with 1/n, you get for z^(1/n) right ?

royal laurel
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yes

crisp niche
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and then you can derive the formula for comlpelx roots

royal laurel
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emm

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let me try

crisp niche
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arguemnt of cosne and sine wil be (ϕ + 2k𝝅) / n, where k = 0, , 2, , ... n - 1

royal laurel
crisp niche
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and ϕ = arg z, arguemtn fo comlelx number z

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yes exactly

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but you need to rememebr ab the period

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of trig fucntions

royal laurel
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But is it related to find the nth-root

crisp niche
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yes

royal laurel
# crisp niche yes

I have no clue, I still can't understand why these "angles have to be equivalent"

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which result in a regular polygon

crisp niche
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let's start this frm : let x = Re(z^1/n) and y = Im(z^1/n)

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then you can derive the eqautiuon of the circle

crisp niche
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yes real part and imagjanry part

royal laurel
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i see

crisp niche
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and take sum fo thier squaRES

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then you get eqaution of circle

royal laurel
crisp niche
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squares

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i meant

royal laurel
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i see

crisp niche
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x^2 + y^2 = R^2

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where radius R is arithmetic root

royal laurel
crisp niche
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yes

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that shwos oyu relation

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to this circle

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where vertices of polygon lie

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in other words, nicer words, every nth root of comexl number is a vertice

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of such polygon

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but due to tri periods they rep[eat itself

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how to say, wioth sme angle disdtance

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repeat every same number of degrees

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to be exact thsi angle distance is

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2kPi / n

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look

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cos (( θ + 2kPi)/n) , the period

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si what i wrote above

royal laurel
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im not sure what do you mean by "take sum for their squares"

royal laurel
crisp niche
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no

royal laurel
crisp niche
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you wrote de moivre

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it s good

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adn now let x be your real part of you wrote

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and y be an imaginary part

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of what you wrote

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and then do this x^2 + y^2

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sum of sqaures

royal laurel
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I see

crisp niche
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to be faster i wrote what you shud get =

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x^2 + y^2 = R^2, whhere R is the nth root of z

royal laurel
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that is (a+b)(a-b)

crisp niche
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no ) i msut make pdf

royal laurel
#

ohhh

royal laurel
# royal laurel

<@&286206848099549185> can someone help continue the proving process

royal laurel
crisp niche
#

this is the part that shows that the root lies on a circle of radius R

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and now, from the period of trigonometric functions, we see that the roots are the vertices of a regular polygon

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the base period is equal T = 2𝝅 / n

royal laurel
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It is terrific

crisp niche
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trig idenity si also used among calcualtiosn but i omit those clear calcualtions

royal laurel
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I see

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Thank you so much for the proof of it

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It is clear and intuitive

crisp niche
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but the conclusion you shdu take from it, is that all roots of comlelx number lies on this circle

royal laurel
crisp niche
#

yes yes

royal laurel
#

Which might result in a line, triangle, or polygon

crisp niche
#

thai is conclusion trival one

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if you can see all circle in your mind, then you can compute those roots

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jsut in mind

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no need formula

royal laurel
crisp niche
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in my pdf, first line

royal laurel
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I see

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I think the geometry perspective is much better and clearer

crisp niche
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yes but soem pl prefer to computer on numbers )

royal laurel
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Thank you for explaining those

crisp niche
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that depends on yoru audience, students

royal laurel
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I will add them to my note, thank you

crisp niche
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yvw)

royal laurel
#

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bleak tiger
#

is there any way that we can get a range of 70 quantile when mean = 80 sd = 10 in standard normal distribution

brisk totem
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might want a better word than range

and the answer is z table

bleak tiger
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not using a z table

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im so confused

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Can we get a "range of X Random varibable" w/o using a ztable?

brisk totem
#

eh, you’re supposed to memorize 1/2/3 stds away and in general it’s intractable do to by hand

bleak tiger
#

im so sorry for bothering but could you show me. an example?

devout snowBOT
#

@bleak tiger Has your question been resolved?

devout snowBOT
#

@bleak tiger Has your question been resolved?

devout snowBOT
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@bleak tiger Has your question been resolved?

devout snowBOT
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@bleak tiger Has your question been resolved?

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@bleak tiger Has your question been resolved?

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stone fjord
#

Hey I need help with proving this:

Let 𝐴 ⊆ ℝ be non-empty and upper bounded. Show that there then exists a sequence (𝑎_𝑛) with 𝑎_𝑛 ∈ 𝐴 for all 𝑛 ∈ ℕ and lim𝑛→∞ 𝑎_𝑛 = sup𝐴.

I tried to define a sequence (a_n) which is defined on A and is corresponding to the Monotonicity criterion so that a_n < a_(n+1)

But I think I'm missing something and doing it completly wrong

stone fjord
#

I did a bit of research and I think i need to work with the upper bounds of A. So that E contains all upper bounds of A so that, a_n < I (with I ∈ E)

#

and we also have sup A = s < I

#

ok

#

I had it in a lecture but i think i didnt got it very well

#

i think i got it

#

you explained it well enough to get me further

#

that's what i needed

#

thank you!

#

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summer edge
devout snowBOT
summer edge
#

This look right?

#

I did it in my head

#

Here ill do it on paper rq

tribal sierra
dry oxide
#

,rccw

woven radishBOT
dry oxide
#

,w derivative of \frac{2}{x-2}

dry oxide
#

@summer edge

summer edge
#

Thx

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astral steppe
#

Discrete math and transitive help her.

Let's say we have the relation {<1,2>,<2,3>,<1,3>,<4,5>}. If we only had {<1,2>,<2,3>,<1,3>} I know it's transitive. But is it still transitive with the <4,5>?

sonic smelt
#

Yeah, the condition of transitivity is not contradicted by including <4, 5>

wooden veldt
#

Yes, <4,5> does not produce any new chains like <x,y> AND <y,z>

astral steppe
#

ok

#

But let's say we add <5,6> in there

#

is it not transitive now?

#

Since we don't have the <4,6>

#

@wooden veldt @sonic smelt

wooden veldt
#

Correct

sonic smelt
#

Indeed

astral steppe
#

Ok thanks for clearing that up for me!

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astral steppe
#

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astral steppe
#

{<1,1>,<2,2>,<1,2>,<3,3>,<4,4>,<3,4>} Why is this one transitive @wooden veldt @sonic smelt ?

sonic smelt
#

Why should it not be transitive?

astral steppe
#

the definition is if x related to y and y related to z, then x must be related to z right?

sonic smelt
#

Right

astral steppe
#

So it's just because y is not related to any z?

lethal walrus
#

hello

sonic smelt
#

What do you mean by that?

lethal walrus
#

can someone help me on math homework

sonic smelt
lethal walrus
#

oh sorry

astral steppe
#

well 1 is related to 2, and 2 is not related to anything else then 2

sonic smelt
#

Yeah

astral steppe
#

therefor it's transitive ?

sonic smelt
#

If you have x = y or y = z, then the condition of transitivity becomes trivially true

astral steppe
#

ok

#

ty

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dim prawn
#

Taken

devout snowBOT
dim prawn
#

How do i know if this function is even or odd?

supple knot
#

,rotate

woven radishBOT
supple knot
#

find f(-x) and see if it equals f(x), which would make it even, or if it equals -f(x), which would make it odd

dim prawn
supple knot
#

wherever you see an x, replace it with -x

dim prawn
#

,rotate

#

This way?

dim prawn
woven radishBOT
supple knot
#

yup

dim prawn
#

So it’s even?

supple knot
#

simplify the inequalities

dim prawn
#

Oh

supple knot
dim prawn
supple knot
#

,rotate

woven radishBOT
supple knot
#

looks good

dim prawn
#

Thanku

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keen crane
#

Is it right that limit of 1/+inf = 1/-inf = 0?

drifting sierra
#

1/+inf and 1/-inf are not numbers

sonic smelt
#

If you meant this
[ \lim_{x\to\infty}\frac1x = \lim_{x\to-\infty}\frac1x = 0 ]
Then, yes, this is right

woven radishBOT
#

A Lonely Bean

keen crane
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lime dome
#

f(n) = 2npi+pi/2

devout snowBOT
lime dome
#

why is this function one to one and onto?

#

sinx=1

#

x=2npi+pi/2

#

sin(2npi+pi/2)=1

#

thats what im supposed to find

#

but

#

idk why its one to one or onto

lavish sigil
#

Technically you can restrict the codomain of any function and that would make it a bijection

lime dome
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delicate wind
#

What are these type of equations called? When I look up adding fractions on khan its not the same as these

winged hazel
#

That’s just adding, subtracting, and multiplying numbers

#

It’s not really a type of equation, it’s just addition subtraction and multiplication

delicate wind
#

How do you go about doing it without a calculator? For the first addition I added each row individually and got the correct number but the second one was way off

winged hazel
#

I mean there’s lots of ways to go about it, there’s probably people better suited to answer your question than me, I just kinda do it so I don’t have a great explanation of how

topaz axle
#

each row individually sounds like the right way and the wrong way at the same time

#

but also "the wrong way" should work too

delicate wind
#

Well the first one I added each row from the right So 1+7+1 9 then 7+1+1 9 then 5+2+1 and 899

#

but the second one doing that I got like 181824

topaz axle
#

yeah that's the right way, each column

winged hazel
#

Are you remembering that when something adds up to say 11, you need to carry a 1 to the next decimal place and add it there?

delicate wind
#

So the 2nd one I star far right 5+8+2+9 = 24

topaz axle
#

yeah, you should get 2 digits, you write the first digit above first row

delicate wind
#

Carry the 2?

topaz axle
#

yes

delicate wind
#

To the next row or first row?

topaz axle
#

4 goes in the answer

delicate wind
#

okay

#

okay perfect I got it

#

so it the subrtracting the same

#

is*

#

anyone here

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atomic shale
#

Hello

devout snowBOT
atomic shale
#

nvm solved it myself lmao

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restive river
devout snowBOT
restive river
#

I'm asked to determine period, amplitude and the eq. of the axis of the trig function

#

then to write equation of function

#

I've determined the following so far

#

period: 4pi
k: 1/2
q: -2

#

how do I determine if this is a sine, cosine or tan graph?

#

or if it's been shifted

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#

@restive river Has your question been resolved?

restive river
#

<@&286206848099549185>

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lavish cypress
#

Is this right correct me if I’m not

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stark sinew
#

Looks good!

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@lavish cypress Has your question been resolved?

lavish cypress
stark sinew
#

what have you tried? Also your previous question was resolved so would have been better to open a new channel

lavish cypress
#

cause inscribed

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@lavish cypress Has your question been resolved?

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#

@lavish cypress Has your question been resolved?

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#

@lavish cypress Has your question been resolved?

restive river
#

@lavish cypress I think the answer is second option

woven radishBOT
#

Aditya gamer

restive river
#

@lavish cypress

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atomic rivet
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@atomic rivet Has your question been resolved?

atomic rivet
#

<@&286206848099549185>

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@atomic rivet Has your question been resolved?

atomic rivet
#

<@&286206848099549185>

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@atomic rivet Has your question been resolved?

atomic rivet
#

<@&286206848099549185>

frozen aurora
atomic rivet
#

whts tht?

#

i think we find

#

x^2y^2z^2 using the equation

frozen aurora
atomic rivet
#

yeah

frozen aurora
#

you should get $xyz(x-y-z)=0$ and $xy-xz-yz=0$

woven radishBOT
#

artemetra

frozen aurora
#

maybe vieta should work somehow

atomic rivet
#

but how?

frozen aurora
#

let me think

atomic rivet
#

@frozen aurora have u cooked the solution

atomic rivet
#

<@&286206848099549185>

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fervent sundial
#

Do you just have to have the triplets memorized or something? Lmao

#

or have euclid's proof for generating triplets memorized?

winter patrol
#

well you should know the most basic one (and you could scale that up)
you don't need to consider that much since 24 is so low

#

3,4,5
5,12,13
are ones you should remember

fervent sundial
#

what if i didn't remember them?

wraith horizon
#

mb, I misread the question

fervent sundial
#

lol

winter patrol
#

if you can't remember 3,4,5
you're stuffed

fervent sundial
#

i know 3,4, and 5

#

i don't see why i need 5,12, and 13 though

#

not so common

winter patrol
#

it comes up quite frequently in trig/geo questions

#

so worth remembering too

#

generating some takes a bit more work, but isn't actually that bad

fervent sundial
#

hmm sure

#

thanks

#

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real topaz
#

Btw
Area of isosceles triangle is
1/2 base x height

But here why do they
Take height = base ?

real topaz
#

I am referring to the last solution in the second pic

devout snowBOT
#

@real topaz Has your question been resolved?

near trout
#

it's isoceles, meaning two sides are equal

#

but it's a right-angled triangle too

#

so the two short sides must be the equal ones

#

because the hypotenuse is gonna be longer

#

so base = height

#

@real topaz

real topaz
real topaz
near trout
#

right

real topaz
#

It's not equal here

real topaz
drifting sierra
#

I think you're confused about what the "base" is

real topaz
#

Hm?

drifting sierra
#

The formula 1/2 base * height works for any triangle, not just isosceles

real topaz
#

Yes

drifting sierra
#

Ok here is an isosceles triangle

#

And here is the same but on its side

#

The "base" of an isosceles triangle can refer to the side that is not equal to the other two, but here the base is just for calculating area

#

It can be any side, as long as you pick the corresponding height (which is perpendicular)

real topaz
#

Oh ok

#

I understand it now :]

drifting sierra
#

And if the triangle is also a right triangle, then you can take the base as one of the legs and the height as the other leg

#

(it should be obvious that the area of a isosceles right triangle is half the area of a square, with the legs being two sides of that square)

real topaz
#

Right. Thx

#

Will be closing now cause I understand the situation now :>

#

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winged imp
#

can anyone help me with Divide Remainder Theorem

winged imp
#

<@&286206848099549185>

pastel dome
#

don't ping helper

#

before 15 min

winged imp
#

sorry

#

uhmm anyone please help me

pastel dome
#

what is the question

#

asking you to do

winged imp
pastel dome
#

no what is the original question

#

is it asking you to simplify?

winged imp
#

It just says here to Divide

winged imp
deep vortex
winged imp
#

i need help ;D

pastel dome
#

use synthetic division

deep vortex
# winged imp yeah how do you solve it?

Well, use the procedure of polynomial long division.

Divide the term of highest order in the dividend through the highest order term in the divisor (p^4/p)

#

You get p^3

pastel dome
#

$p^3−p^2−5p+5$ with a remainder of -1

deep vortex
#

Multiply p^3 with (p + 6) and subtract that from the dividend

#

Repeat

woven radishBOT
pastel dome
#

,w synthetic division

woven radishBOT
pastel dome
#

look into that

winged imp
#

even though if i read that i'll still won't get it

pastel dome
#

no search up a youtube video on that

#

i don't have a paper rn and it's hard tos how

winged imp
#

those this work?

#

P(-6) = (-6)^4 + 5(-6)^3 - 11(-6)^2 - 25(-6) + 29
= 1296 - 1080 - 396 + 150 + 29
= -1

#

hello?

pastel dome
#

yes

#

the remainder is -1

#

as specified

#

but this won't yield the quotient

winged imp
#

Remainder Theorem?

pastel dome
#

usel long division/modular arithmetic/synthetic division to get the quotient

#

synthetic division will be the easiest

winged imp
#

is this the one?

#

is this what you trying to mean?

pastel dome
#

yes

#

it is this one

winged imp
#

can i ask?

#

how did it to 6?

pastel dome
#

that's just

#

$p^3*6$

woven radishBOT
pastel dome
#

search up a youtube video

winged imp
#

alright

#

.close

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edgy jasper
#

how can i solve these two?

devout snowBOT
edgy jasper
#

<@&286206848099549185>

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limpid dome
#

hi

devout snowBOT
limpid dome
#

i get 64 but there is no 64

#

Number of cubes along the length = 8cm / 2cm =4

#

Number of cubes along the width = 8cm / 2cm = 4

#

Number of cubes along the height = 8cm / 2cm = 4

drifting sierra
#

That would be how many are in the box, not touching the box

limpid dome
#

4x4x4=64

final scarab
#

oh shit my bad.

#

didnt go thru the q

limpid dome
#

sjdsjdjsd

#

what should i do

restive river
#

8^3/2^3

#

İt is this rigth?

drifting sierra
restive river
drifting sierra
restive river
#

Ohh

#

Ok

limpid dome
#

Number of cubes along the length = 8cm / 2cm =4
Number of cubes along the width = 8cm / 2cm = 4
Number of cubes along the height = 8cm / 2cm = 4
4x4x4=64

#

i do this

#

what is the problem

restive river
#

Oh ok

#

İ read it wrong

limpid dome
drifting sierra
#

?

#

You came here for help, if you can do it then do it

limpid dome
#

i write i can`t😂

drifting sierra
#

Uh ok, language barrier I guess

limpid dome
#

😂

restive river
#

That doesnt works nvm

devout snowBOT
#

@limpid dome Has your question been resolved?

limpid dome
#

finish

supple knot
#

.close

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real cove
#

How can I integrate this through partial fraction decomposition? Seems like I'm back where I started

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supple knot
real cove
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supple knot
#

$\int \frac{du}{u^2+1} = \arctan(u) + C$

woven radishBOT
#

riemann

real cove
#

.reopen

devout snowBOT
#

supple knot
#

yes

#

you have to try different trig subs

real cove
#

I did a trig sub on the other half

#

I don't know how to do it here since it is squared

bold shale
real cove
bold shale
#

You can write it as $\int ( \frac{n}{(n^2+1)^2} + \frac{1}{(n^2+1)^2} ) dx$
Then the first one will be a simple u-substitution and the the second one trig substitution

woven radishBOT
#

Alireza

You can write it as $\int \( \frac{n}{(n^2+1)^2} + \frac{1}{(n^2+1)^2} ) dx$
Then the first one will be a simple u-substitution and the the second one trig substitution
```Compilation error:```! LaTeX Error: Bad math environment delimiter.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...                                              
                                                  
l.57 You can write it as $\int \(
                                  \frac{n}{(n^2+1)^2} + \frac{1}{(n^2+1)^2} ...

Your command was ignored.
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real cove
#

The second one I could do n = tanx and I end up with sec^4(x) ?

bold shale
real cove
#

Fck

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Well played. Couldn't do this on an exam and it was bugging me thank you

real cove
#

.close

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steady violet
#

I got stuck.. what do I do next? or is my answer already wrong? (note: we still didn't take L'hopital) ||(also.. the answer is -9/50 showed in this booklet)||

steady violet
#

this is the referance

upper schooner
#

[don't forget the limits btw]

steady violet
steady violet
upper schooner
steady violet
#

wait I think I can solve it now

upper schooner
steady violet
upper schooner
#

Welllllll also another comment too, assumedly you got those sin(5h) through Pythagoras, but you'd introduce a negative sign when that happens

steady violet
upper schooner
woven radishBOT
#

@upper schooner

upper schooner
steady violet
upper schooner
#

Alternatively multiply by h^2/h^2

upper schooner
woven radishBOT
#

@upper schooner

upper schooner
#

Like $\cos^2(5h) - 1 = -(1 - \cos^2(5h)) = -\sin^2(5h)$

woven radishBOT
#

@upper schooner

steady violet
#

ohhhh yeah

#

I forgot about that

#

thanks so much!

upper schooner
#

SCgoodjob2 no problem catlove

steady violet
#

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sleek panther
devout snowBOT
sleek panther
#

I moved to equal = x^2 + 2x-3

#

factor = (x-1)(x+3)

#

so i put in

#

[-3,1]

#

but it say no good 4 the answer

prime egret
#

x^2 + 2x -3 >= 0 tho

pastel dome
#

not equal****

prime egret
#

Think about the shape of quadratic

sleek panther
#

i mean between x intercepts is below zero

prime egret
#

Right

pastel dome
#

draw the thing out with x intercepts at 1 and -3

prime egret
#

Listen to my student

sleek panther
#

0 <= x^2+2x-3, i think x^2 +2x -3 => 0 is equivelent

#

so i had wrong

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because its opposite

pastel dome
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what

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=

sleek panther
#

yes is true

sleek panther
main marlin
#

=>

sleek panther
#

oh yeah = matters

#

.close

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#
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pastel dome
#

@prime egret .

prime egret
dry oxide
#

@prime egret sir, can i be your student too?

prime egret
#

@pastel dome

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What do you think

dry oxide
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pwease

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i beg you

prime egret
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@pastel dome

pastel dome
#

hmm

#

he can be apprentice...

dry oxide
#

oh

#

ok..💔

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lethal meadow
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lethal meadow
#

I’m not too sure how to set this equation up. As this is a harmonic oscillator it has to he a second order ode and idk how to make that

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#

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floral badger
#

Order f(x) f(0)
0 7sin5x 0
1 35cos5x 35
2 -175sin5x 0
3 -875cos5x -875
4 4375sin5x 0

devout snowBOT
floral badger
#

im stuck

timber pebble
#

oh thats nice of them to provide you all this information

floral badger
timber pebble
#

or just find the infinite one

floral badger
#

but i cant see the way to express the pattern

floral badger
timber pebble
#

well there are a few ways

floral badger
#

from n=0

timber pebble
#

one is to know the series

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for sinx i mean

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so i guess thats out lol

timber pebble
#

you can alternatively work out the maclaurin series for $e^{ix}$

woven radishBOT
#

jan Niku

floral badger
#

idk any other ways

timber pebble
#

because $e^{ix} = \cos x + i \sin x$

woven radishBOT
#

jan Niku

timber pebble
#

you just take every piece of the series with an i attached to it

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and the series for e^(ix) is very easy

timber pebble
#

work out the series for sinx

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just sinx

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using $f(x) = \sum _{n=0} ^\infty \frac{ f^{(n)} (0) }{ n! } x^n$

woven radishBOT
#

jan Niku

timber pebble
floral badger
#

but just sinx

#

?

timber pebble
#

i mean we can kind of walk through it, if you want

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but i dont wanna just start rattling it off i fyou want the practice

floral badger
#

no i dont really understand it to well so

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its more learning atm

timber pebble
#

okay

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well we can walk through it

timber pebble
woven radishBOT
#

jan Niku

timber pebble
#

but it doesnt end up being so bad

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f here is sine

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whats the zeroth derivative of sine evaluated at 0?

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(no derivative)

floral badger
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sine

timber pebble
#

yea

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and at x=0, its just 0

floral badger
#

ye

timber pebble
#

so, for the n=0 term, it actually vanishes

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you found something like this in your table

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we can maybe notice that like

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the second derivative of sin(x) is -sin(x)

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which is also 0 at 0

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so it seems like every other term is going to vanish

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start with n=0,2,4,...

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now we gotta do the odd derivatives

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whats the first derivative of sine? what is it evaluated at 0?

floral badger
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cose

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then 0

timber pebble
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no

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cos(0) = 1

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yea?

floral badger
#

ye

timber pebble
#

alright

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we know the next derivative up is -sin(x) and thats 0

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whats the derivative of -sin(x)?

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(were on term n=3, now)

floral badger
#

-cosx

timber pebble
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at 0?

floral badger
#

-1

timber pebble
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yup

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so, do you think you can write out $f^{(n)} (0)$ for any n?

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it seems like 0, 1, 0, -1, ...

woven radishBOT
#

jan Niku

floral badger
#

this is where i get stuck

timber pebble
#

well, lets start with a guess

floral badger
#

am i looking at the answers or derivs

timber pebble
woven radishBOT
#

jan Niku

timber pebble
#

heres something that might help

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$f(x) = \sum _{n=0} ^\infty \frac{ f^{(n)} (0) }{ n! } x^n$

woven radishBOT
#

jan Niku

timber pebble
#

can you remember which terms are 0?

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n=0,2,4,... right?

floral badger
#

evens

timber pebble
#

yea

#

so lets change our index to just have odds

floral badger
#

f(n+1)

timber pebble
#

say like... n=2m+1 for m=0,1,2,3,....

timber pebble
timber pebble
floral badger
#

ye 2 makes it even +1 makes it odd

timber pebble
#

alright

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so we can replace n with 2m+1 here

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and let m=0,1,2,3,... instead

floral badger
#

ok

timber pebble
#

$f(x) = \sum _{m=0} ^\infty \frac{ f^{(2m+1)} (0) }{ (2m+1)! } x^{2m+1}$

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okay, that term in the numerator is asking for the odd terms of the derivative evaluated at 0

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before we reindexed, we had 0, 1, 0, -1, 0, 1, .....

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so if we just pull out the odd terms, what are they?

floral badger
#

0,0,0

timber pebble
#

well, thats not right

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we are looking for the odd terms

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it just starts at 0

floral badger
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1, -1, 1

timber pebble
#

yea