#help-39

1 messages · Page 191 of 1

silk vine
#

can i see

mighty meteor
#

here

silk vine
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thing is

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you got the answer right

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using the substitution earlier

mighty meteor
#

this too

mighty meteor
silk vine
#

this is right taking into account

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its all multiplied by 2

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and +1

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instead of -1

mighty meteor
#

oh right

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oh wait

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thats right

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my bad

silk vine
#

its not the form they want

mighty meteor
#

would this work tho?

silk vine
#

but i think its pretty good

mighty meteor
#

like, i dont wanna redo it for nothin

silk vine
#

im pretty sure your other solution is right too

#

ill have a look

mighty meteor
#

ill just redo it then

silk vine
#

the whole thing looks right

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im pretty sure its the same form but I wouldn't know how to show the 2 are the same using trig identities

mighty meteor
#

ill show u this time

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btw, correct answer is d)

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so like

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i think i got it

silk vine
#

aw man

mighty meteor
#

ill show u

silk vine
#

appreciate it

mighty meteor
#

here you go

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ignore the first line

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its wrong

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it starts from the second line

silk vine
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thats very nice

mighty meteor
#

yup

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it is

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ill send you the next one

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if you get tired

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or bored

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or just dont wanna do anymore

iron stream
#

Yo hii new question?

silk vine
#

nah i dont mind

mighty meteor
#

then just tell me

mighty meteor
silk vine
#

I need to prep for the integration bee antway

mighty meteor
#

this ones should be way easier, thats what the book thinks at least

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ill send them now

silk vine
#

so as much integgrtion as possible i good

mighty meteor
#

oh shit

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my phone is dying, imma go grab a charger

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brb

silk vine
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i have enough hell exercises

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but ill take some more

mighty meteor
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im on my laptop, but like i need it to take pics

mighty meteor
#

also, i dont understand volumes with integrals, but ill leave those for tomorrow

silk vine
#

volume integrals are actually not to bad

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cause its basically nothing new

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cause they wont make you do a difficult substitution

mighty meteor
#

here the exercise

mighty meteor
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but they require it for the uni exam

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which means that i gotta study them by myself

silk vine
#

yikes

silk vine
mighty meteor
#

it shouldnt be

silk vine
#

splitting it up seems to work nicely

mighty meteor
#

ight

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imma do exactly that

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i think i know what ure talking about

iron stream
#

The fact that there's an easier way

silk vine
#

did i miss something

iron stream
#

Divide numerator and deno with x⁴

silk vine
#

partial fractions seemed obvious

iron stream
silk vine
#

thats very clever

iron stream
silk vine
mighty meteor
#

right

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so i remember what i didnt get at this exercise

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so what do you guys think the answer is?

silk vine
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I got c

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but i kinda rushed it so not too confident

mighty meteor
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oh damn you are quite far from the answer

silk vine
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a pity

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ill check my workings

mighty meteor
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here

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so from that it would like the answer is a)

iron stream
mighty meteor
#

but then what is very similar to a)?

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its e)

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and e) is hte answer

mighty meteor
#

then you are a god at maths

mighty meteor
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i am not a god at maths tho

silk vine
iron stream
#

But I was 18 then

silk vine
#

i did it and it worked out like crazy

mighty meteor
silk vine
#

i just have no idea how you spotted it

iron stream
mighty meteor
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didnt u say ure 16? or am i confusing you with someone else?

mighty meteor
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oh

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damn

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never mind then

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yea idk, just check what i did

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and tell me what i did wrong

silk vine
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well not substitutions but like

iron stream
silk vine
#

that came out of noweher

mighty meteor
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exactly

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like

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i dont wanna be mean or anything

silk vine
mighty meteor
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but sometimes it seems like u dont come up with these yourself

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welp, i think hes looking them up

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but it doesnt matter

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i personally could never come up with these subs

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because also

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its not like they are universal

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no

silk vine
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well in the end that substitution got me the right anser i think

mighty meteor
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its very specific subs that would only work in THIS specific exercise

mighty meteor
#

this

silk vine
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idk some people are crazy good at spotting

mighty meteor
mighty meteor
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to spot these things

silk vine
mighty meteor
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right

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i got a

silk vine
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the substitution just solves the entire question its crazy

mighty meteor
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which is e but with the denom reversed

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dude, for the love of god

silk vine
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oh no way i actually got this answer as well

silk vine
iron stream
mighty meteor
#

thats for sure

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but where

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actually no its not about the negative sign

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it would have to be (1-x)(1+x) to get 1- x^2

silk vine
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oh well

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thats your negative sign

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swap the bottom multiply the entire thing by -1

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and that flips the log

mighty meteor
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huh?

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i dont get it

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also

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this is the solution from the solution book:

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which would mean that im right

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but then, the solution from the multiple choice book

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says its e)

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i hate this book

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i will burn it

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i will do to it what they did in germany in ww2

silk vine
mighty meteor
#

what did i do wrong?

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if it was - ln of that

silk vine
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no i made a mistake when i saidyou could minipulate it

silk vine
mighty meteor
#

then you would get ln (x^2-1)/x^3

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which is just wrong

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if it were e) there shouldve be a -ln

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yea i think im right

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the book just made a typo

silk vine
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man im gonna check an integral calculator

mighty meteor
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bro, XOR-11's inhumane formula did us dirty

silk vine
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integral calculator has same answer as you

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mustve been a tyypo

mighty meteor
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,w integrate [x^2-3]/[x^3-x]

silk vine
jolly parrotBOT
silk vine
#

yup

mighty meteor
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this motherfucker

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i will kill wolfram

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WHERES THE MISTAKE

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I MADE NO MISTAKE

silk vine
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thats the same answer as you

mighty meteor
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i got x^2 - 1

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he got the correct answer

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the one from the book

silk vine
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wild the integral calculator is arguing with wulfrum alpha

mighty meteor
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is it?

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no way

silk vine
mighty meteor
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wow

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i asked chatgpt too, but his off his goddamn gourd

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he god some insane result

silk vine
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every chatgpt answer is nonsense

mighty meteor
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hes just a little special

silk vine
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thats it

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differentiating

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your answer is right

iron stream
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It's always advised to consider the 1-x² form

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You have considered ln(x²-1) and that's causing the issue

mighty meteor
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ok so, the correct answer is mine

iron stream
iron stream
#

Maybe because then, the function is defined for trigonometric functions

silk vine
#

how did you spot

iron stream
silk vine
#

how did you spot dividing everything by x^4

iron stream
silk vine
#

insane

mighty meteor
silk vine
#

like once i see it it makes sense

mighty meteor
silk vine
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i looked up derivative calculator

mighty meteor
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wait

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both answer

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a) and e) differntiate the same

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this is some bullshit

silk vine
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i got it differently when i put in d

mighty meteor
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it was never d

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sorry

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i meant e)

silk vine
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weird

mighty meteor
silk vine
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this is a isnt it

mighty meteor
mighty meteor
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i put both a) and e)

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both differentiate the same

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but the integral looks different

silk vine
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wowza

mighty meteor
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wait

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,w differentiate ln(x^3/(1-x^2))

jolly parrotBOT
silk vine
#

wulfrum???

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oh its fine

mighty meteor
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,w differentiate ln(x^3/(x^2-1))

jolly parrotBOT
mighty meteor
#

alright

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i will consider this exercise solved

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up for more?

silk vine
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i dont even know what to make of a and e both being correct

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i thought it was uniqu

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i guess cause when you integrate its modulus

silk vine
mighty meteor
mighty meteor
#

oh wait

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yes you are right

silk vine
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like integral 1/x = ln|x|

mighty meteor
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so the correct answer is e)

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because its modulus

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DAYUMMMM

silk vine
#

but also a

mighty meteor
#

no no

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it isnt

silk vine
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why is a not counted

mighty meteor
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because x belongs to (-1, 0)

silk vine
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ohhh

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amazing

mighty meteor
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one sec i gotta write it dow

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down

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here

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this is the next one

silk vine
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okie

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oh is this just an integrl

mighty meteor
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it is

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i just didnt get the right answer

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these are very easy ones

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but ill get back to the super duper hard ones after this one and the next one

silk vine
#

is this one c

mighty meteor
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well i be damned

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it is

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ill do it quickly

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maybe i get the answer right this time

silk vine
#

cool

mighty meteor
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the fact that you did it in your head

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woww

silk vine
#

didnt do it in my head

mighty meteor
#

alright

silk vine
#

no chance

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wrote down very fast

mighty meteor
#

i will have to translate the next one

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so hang on

silk vine
#

lovely

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its not a

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and its not f

mighty meteor
#

i agree

silk vine
#

Im gonna say c and e are wrong

mighty meteor
#

huh?

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i actually thought that e might be right

silk vine
#

im sure c is wrong

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im not too sure why there would be infinitely many primitives

mighty meteor
#

ill check

silk vine
#

interesting

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if a function has one primitive it has infinitely many primitivs

mighty meteor
#

well yea

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its because of the constant

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c

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this wouldnt be the same if it were a defined integral im pretty sure

silk vine
#

maybe b and e then

mighty meteor
#

how about d)?

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oh wait

silk vine
#

forgot what that does

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im looking it up

mighty meteor
#

it continuous so it does have Darboux's property...maybe

silk vine
#

If f : I → R is a function, and I ⊂ R is an interval, f has
the Darboux property if for any a, b ∈ I, a < b and for any λ ∈ (f(a), f(b)) ∪
(f(b), f(a)) there is c ∈ (a, b) such that f(c) = λ.

#

aw man

mighty meteor
#

no no

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it does have darboux's property

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because it says that there is an f'(c) = gama

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which is true even if the function is not differntiable on R

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it only needs to be continuous and differentiable on an interval

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so it does have it

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so d) is wrong

silk vine
#

lovely

#

this darboux property stuff is really coming out of nowehere

mighty meteor
#

im pretty sure

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like he helped Fermat

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and then fermat helped Rolle

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complicated stuff

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doesnt matter

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anyway

silk vine
#

darboux is a good chap

mighty meteor
#

we are left with b) or e)

silk vine
#

he made darboux sums

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can it not be multiple

mighty meteor
silk vine
#

cause b implies e

mighty meteor
#

thank god i dont know em

silk vine
#

its not too bad its just integration

mighty meteor
#

no, it cant ever be multiple

silk vine
#

then im gonna say e

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cause b means that at some points the whole functions is negative

mighty meteor
#

oooh, its not b) because it sais on R

silk vine
#

which doesnt make sense

mighty meteor
#

and that would mean that c) is correct too

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which isnt

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because its not differentiable on R

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aha

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insane

silk vine
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why dont you think its e

mighty meteor
#

no, i do think its e

silk vine
#

me as well

mighty meteor
#

i just said that b) is wrong

silk vine
#

oh apologies

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is that right?

mighty meteor
#

yea

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its e)

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im almost finished with this chapter

silk vine
#

hoorays

mighty meteor
#

i can believe it

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i almost finished the whole integration part from this book

silk vine
#

in how long

mighty meteor
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i only got the last 10 turbo hard exercises at the end

mighty meteor
#

4 days

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im not sure

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it may have been 5

silk vine
#

thats insanely fast

mighty meteor
#

yea, i work 8 hours a day

silk vine
#

lets see these hard exercises

mighty meteor
#

at math

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or well, not just math

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its math and physics

mighty meteor
#

i need a break

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can i be back in like 30 mins?

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ill dm you in private

silk vine
#

sure

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Ill probably be off by then

mighty meteor
#

and ill close this chat

mighty meteor
#

you'll be off in half an hour?

silk vine
#

good integrating today though

mighty meteor
#

eh, its fine, we can just do some more tomorrow

silk vine
#

im gonna divide everything by x^4 from now on just in case

#

bye bye

mighty meteor
#

same

#

bye

#

.close

pearl pondBOT
#
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pearl pondBOT
#
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Show your work, and if possible, explain where you are stuck.
After 15 minutes, feel free to ping <@&286206848099549185>.
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gusty flume
#

Prove the following:
For any weighted, undirected graph $G=(V,E)$:
For any proper subset $U\subset V$ of vertices
and any edge $e={u,x} \in E$ with $u \in U$ and $x \in V\setminus U$
and $w(e)= \min { w({u', x'}) \mid {u', x'} \in E, u' \in U, x' \in V\setminus U }$:
There exists a minimal spanniung tree $T$ with $e\in E(T)$.
And if $w(e)$ is strictly smaller than any other edges between $U$ and $V\setminus U$, then $e$ is included in all possible minimal spanning trees.

jolly parrotBOT
#

Bob Goldham

gusty flume
#

My idea was the following

#

case distinction:
We consider the graph (V, E\{e})
it is either connected or not connected.
If it is not connected, then e must be in any spanning tree of G whatsoever, including any minimal spanning tree.

#

If it is connected, then the minimal property of $e$ guarantees that any edge $e'$ between $U$ and $V\setminus U$ has at least weight $w(e)$.
If the weight is larger for all such edges, then the spanning tree of $G'$ is no longer a minimal spanning tree of $G$.

So every minimal spanning tree of $G$ contains at least one edge of exactly weight $w(e)$.

If there is more than one such edge, then we could remove all except (any arbitrary) one of them and still have a minimal spanning tree, since they all connect the same subsets of vertices and have the same weight. Thus the resulting spanning tree must always remain minimal.

jolly parrotBOT
#

Bob Goldham

gusty flume
#

Is this correct?

pearl pondBOT
#

@gusty flume Has your question been resolved?

pearl pondBOT
#

@gusty flume Has your question been resolved?

pearl pondBOT
#
Channel closed

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Use .reopen if this was a mistake.

gusty flume
#

.reopen

pearl pondBOT
#

pearl pondBOT
#

@gusty flume Has your question been resolved?

pearl pondBOT
#

@gusty flume Has your question been resolved?

pearl pondBOT
#

@gusty flume Has your question been resolved?

harsh idol
#

try pinging helpers

#

or opening a new help chat

#

you can ping helpers every 15 mins

brave sluice
#

you didn't define G'

#

but i assume G' is (V, E{e})

#

i don't think the proof is correct

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you said this but

#

isn't this a counter example?

pearl pondBOT
#

@gusty flume Has your question been resolved?

pearl pondBOT
#
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#
Available help channel!

Send your question here to claim the channel.

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

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

exotic crane
#

A bucket was sold at 8% loss had it been sold for 56₹ more there would have been a gain of 8% what is the cost price of the bucket?

cinder thistle
#

so

#

let us the that was p

#

we have

#

p(1+8/100)-p(1-8/100) = 56

#

right?

exotic crane
#

yeah

cinder thistle
#

so

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p(16/100)=56

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right?

exotic crane
#

uh maybe

#

im not sure

exotic crane
#

should i show my working?

cinder thistle
#

sure

exotic crane
cinder thistle
#

56 = 16/100 x

#

it should be

exotic crane
#

how?

cinder thistle
#

108/100 x - 92/100 x

(108-92)/100 x

16/100 x

exotic crane
#

uh yeah

#

oh

#

i got it

#

thanks

#

.close

pearl pondBOT
#
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pearl pondBOT
#
Available help channel!

Send your question here to claim the channel.

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

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

rapid wagon
#

$\lim_{x \to 2^-} \frac{\sqrt{x^2-4}}{|x-2|}$

jolly parrotBOT
#

prograce

rapid wagon
#

Help please

cinder thistle
#

Does not exist, or are you talking in complex numbers?

rapid wagon
#

No, real

#

Why?

#

I got 0 idk

vagrant trout
#

x - 2 > 0, x>2, so undefined limit... can't do left side limit only right side

rapid wagon
#

Oh

vagrant trout
#

Because if x-2<0 it becomes 2-x so it's just 2-1.9999999 which approaches 0 and it's undefined

pearl pondBOT
#

@rapid wagon Has your question been resolved?

#
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Use .reopen if this was a mistake.

#
Available help channel!

Send your question here to claim the channel.

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

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

mighty meteor
#

i need help with this

pearl pondBOT
sharp smelt
#

multiply and divide by $\sqrt{e^{x}+1}$

mighty meteor
#

mhm, i think i tried it

#

let me try again

sharp smelt
#

oops

#

my bad

mighty meteor
#

thats for sure the right approach

jolly parrotBOT
#

math rocks(wai)

sharp smelt
#

I'm confused

mighty meteor
# sharp smelt my bad

no no, i think that its the right approach, i just didnt do the calculations right probably

#

let me retry real quick

#

i think that maybe it would better to multiply by $\sqrt{e^{x}-1}$

jolly parrotBOT
#

Gustavo

mighty meteor
#

because then when you do the sub for $e^{x}$ you get something a little better, maybe

jolly parrotBOT
#

Gustavo

mighty meteor
#

because this is what you get otherwise

sharp smelt
#

huh?

#

$

#

$\int \frac{e^{x}+1}{\sqrt{e^{2x}-1}}$ is what you should get

jolly parrotBOT
#

math rocks(wai)

mighty meteor
#

oh yea sorry

#

i got confused and mixed stuff up

sharp smelt
#

That makes it easier I think?

mighty meteor
#

yea yea, thats what i was thinking too

#

but then the problem is that you now have u*sqrt(u^2-1) in the denom

sharp smelt
#

You can start with e^x=u

mighty meteor
#

yea thats what i did

#

thats why theres the u down at the denom

sharp smelt
#

ah, okay

mighty meteor
#

yea

sharp smelt
#

so first split this into the sum of two integrals

mighty meteor
#

so then i thought of breaking the integral into two

mighty meteor
sharp smelt
#

Think of a way to integrate $\frac{1}{\sqrt{e^{2x}-1}}$ now

jolly parrotBOT
#

math rocks(wai)

mighty meteor
#

idk why you put it back in e^x

#

i think the u sub looked better

#

alright

#

i think i got it

sharp smelt
#

Yeah,but when you let $e^x=u$, you get $e^xdx =du$

mighty meteor
#

i almost did it

jolly parrotBOT
#

math rocks(wai)

sharp smelt
#

not $(e^x+1)dx=du$

#

righ

jolly parrotBOT
#

math rocks(wai)

mighty meteor
#

and dx = 1/u du

#

which is great actually

sharp smelt
#

wait, how did you you get $dx= du/u

mighty meteor
#

e^x=u

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therefore x=ln u

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therefore dx= du/u

sharp smelt
#

ah, that works too

mighty meteor
#

its just a basic trick, idk if you knew that a= e^(lna)

mighty meteor
#

ill show you what the problem is tho

sharp smelt
mighty meteor
#

first of all though

#

do you understand my handwriting?

sharp smelt
#

yes

mighty meteor
#

because i will show you a picture

sharp smelt
#

looks right to me

mighty meteor
#

mhm

#

now look at the multiple choice

#

the problem is

#

we gotta figure a way out to turn arcsin in arccos

#

because i checked and d) is indeed the right one

sharp smelt
#

recall the relation between arcsin and arccos

mighty meteor
#

but i have arcsin not arccos

sharp smelt
#

arcsin(x)+arcos(x) = π/2

mighty meteor
#

soooooooo

#

what does that mean?

sharp smelt
#

well, I think in your working it should be -arcsin(-1/u)

sharp smelt
jolly parrotBOT
#

math rocks(wai)

sharp smelt
#

use this

mighty meteor
#

how?

#

so arcsin x = pi/2 - arccos x

sharp smelt
#

how is this identity true?

mighty meteor
#

how do i use it here?

sharp smelt
#

recall that π/2+C=C here as C is just an arbitrary constant

mighty meteor
#

and also

#

is arcsin odd or even?

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like

#

is arcsin -x = -arcsin x?

#

or maybe arccos -x = -arccos x?

#

cuz otherwise, this is still not doing it

sharp smelt
mighty meteor
sharp smelt
#

,w is arcsin(-x)=-arcsin(x)

mighty meteor
#

ill write it down real quick

#

1 sec

#

btw

#

i got more integrals to solve

#

you wanna help me more?

#

or should i make another help channel?

sharp smelt
#

or actually, I have some work to do now

mighty meteor
#

ah oki

#

no prob

#

cya

sharp smelt
#

open a new help channel, if I'm done by then,I'll try to help

mighty meteor
#

.close

pearl pondBOT
#
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pearl pondBOT
#
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#

cinder bane
#

Refer to #❓how-to-get-help to know ho to get help probably
And also just ask the question, don't ask to ask, this will just consume more time for you.

#

It would be faster for you and the helpers to just ask the question

#

.close

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#
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quick sand
#

I have a very simple question.
I have got a math idea, which I'm able to prove it, but there is no any application for that, and I don't have any reason for doing this, just curiosity.
I'm an UG student, and the idea is about set theory.
So question is, shall I open this with my professor? or it's very bad idea? Thanks

open rivet
#

if its a problem, and youre able to solve it, why not?

regal herald
#

whats your concern here?

halcyon venture
#

Are you sharing your idea?

unkempt yacht
open rivet
#

there have been plenty of times where mathematicians discover some maths and then like 100 years later then find it has applications

vagrant trout
#

Well you can share your idea and others might find an application for it.

iron stream
#

@quick sand Read A mathematician's apology by gh hardy

pearl pondBOT
#

@quick sand Has your question been resolved?

quick sand
quick sand
#

I haven't constructed my idea into papers properly, but I do it. And I'm able then to prove and setup relations and properties of my stuff.
So if it's a normal thingy, then I'm going to open it with my prof soon. I'm just too scared my prof finds it very nonsense since there is no application or reasoning for that, although he's a pure math guru as well.

pearl pondBOT
#
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gusty flume
#

$x^3-3x^2+3x-7=3p$

pearl pondBOT
jolly parrotBOT
#

Bob Goldham

gusty flume
#

I want to solve for x, p is a variable

#

Is there any simpler way than the Cardano formula?

#

$x^3-3x^2+3x-(3p+7)=0$

jolly parrotBOT
#

Bob Goldham

worthy lance
#

Do you know (a-b)^3?

gusty flume
#

=(a²-2ab+b²)(a-b)
=(a³-2a²b+ab²)-(a²b-2ab²+b³)
=a³-3a²b+3ab²+b³

#

=a³-b³-3ab²+3a²b

#

that?

worthy lance
#

What do you have from that in your original

#

Also

#

Is -b^3

#

3a^2b and -3ab^2 too

#

In any case

#

You have almost all

#

For (x-1)^3

#

Just split -7 into -1-6

gusty flume
#

(x-1)³=
x^3-3x^2+3x-1

gusty flume
worthy lance
#

So (x-1)^3-6

gusty flume
#

is just (x-1)³-6=3p

worthy lance
#

= 3p

gusty flume
#

is there a name for this formula? like the binomial formula for (a-b)²?

worthy lance
#

(x-1)^3=6+3p

#

Cubic root both sides

#

Cube of a binomial

gusty flume
#

So i get

#

$x=\sqrt[3]{3p+6}+1$

jolly parrotBOT
#

Bob Goldham

gusty flume
#

alright, thanks!

#

.close

pearl pondBOT
#
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pearl pondBOT
#
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stiff mauve
#

can someone help

pearl pondBOT
stiff mauve
#

ill try to explain where i'm at right:

#

i know column [1 1 1 1 1 1] transpose is a solution

#

i now need to find solutions where ax = 0

#

to get the set of all solutions of the system Ax = [ 1 1 1 1] transpose

stiff mauve
#

i dont know how to continue

#

anyone?

tropic saddle
#

after you reduce [A | 0], what do you get

stiff mauve
tropic saddle
#

and then?

stiff mauve
#

x2 = x4 - x5

#

x3 = -x4

#

x6 = 0

#

x1 = x4 = x5 = free

#

ohhh righttt

#

your presence was enough thanks i understand it now

warm yew
#

heys

#

(1,1,1,1,1,1) + b(0,1,-1,1,0,0) + c(0,-1,0,0,1,0)

#

a,b,c are real numbers

#

whatever

warm yew
stiff mauve
warm yew
#

Where tf the 1 come from

stiff mauve
#

we need to find every possible solution of ax = [1, 1, 1, 1] right

#

one possible solution is when x = [1 1 1 1 1 1]

warm yew
#

oh yeah

pearl pondBOT
#

@stiff mauve Has your question been resolved?

#
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plush sundial
pearl pondBOT
versed mica
plush sundial
#

im getting lambda as 23

#

but in my key its given 28

versed mica
#

!show

pearl pondBOT
#

Show your work, and if possible, explain where you are stuck.

plush sundial
#

here is my attempt

#

ig u wont understand what i wrote

versed mica
#

it is hard to follow

plush sundial
#

ok ill explain

#

the given eqn of the normal is y=2x-lambda

#

slope of normal is 2

#

so slope of tangent is -1/2

#

and i differentiated the parabola eqn and got dy/dx as slope

#

assumed the point of intersection as y itself (got too lazy lol)

#

and equated the slopes

#

from there i got y as (-6)

#

feel me?

versed mica
#

yep

plush sundial
#

aight after that i put the value of y in the parabola eqn

#

got x as 11

#

so the point is (11,-6)

#

to where the tangent is drawn

versed mica
#

yea 11,-6 is good

plush sundial
#

then i used y-y1 = m(x-x1)

#

for eqn of normal

#

x1,y1 = 11,-6

versed mica
#

what

#

just use the equation of the normal
line

#

y = 2x - lambda

#

y = -6

#

x = 11

#

-6 = 22 - lambda

#

lambda = 28

plush sundial
#

holy

#

but why was my method wrong?

#

like again equating it

versed mica
plush sundial
#

like i got the POI and i have the slope m

#

x1,y1 = 11,-6

#

oh shit

#

ye i got it

#

man brain crashed

#

thx tho for confimation

#

.close

pearl pondBOT
#
Channel closed

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plush sundial
#

.reopen

pearl pondBOT
#

plush sundial
#

i hv another doubt

#

im a lil confused in this one

#

@versed mica srry for ping

vagrant trout
#

first complete the square, get the radius

#

then calculate the distance between the center of the circle and the point you got (1,3)

#

call it d for distance

median monolith
#

hello guys sorry i need help about a math thing

vagrant trout
#

then also calculate the distance between the point (1,3) and any point on the circle

plush sundial
vagrant trout
#

call it D

vagrant trout
#

then max distance is

#

d+D

median monolith
plush sundial
#

wont it be d + radius?

median monolith
#

just asked everyone not just you :>

vagrant trout
#

yeah

#

d + radius

#

as any point on the circle

#

is just the ending point of the radius

plush sundial
#

oh ye got it

#

d=7, radius = 4
ans 11

#

ggs

vagrant trout
#

yes

median monolith
#

rookies

#

btw i am working on uhh some kinda integrals that has circle in middle of em

vagrant trout
#

wait

#

open a new one

#

in available

#

go ina ny help channel

plush sundial
vagrant trout
#

in available

plush sundial
#

ill close this

#

.close

pearl pondBOT
#
Channel closed

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warm current
pearl pondBOT
#
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pearl pondBOT
jolly parrotBOT
#

Simon James B
Compile Error! Click the errors reaction for more information.
(You may edit your message to recompile.)

pearl pondBOT
#
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rancid steppe
#

√x^2 -6x +25 + √y^2 +8y+ 41 <= 9 \newline √x^2 - 6x + 9 - 9 +25 + √y^2 + 8y + 16 - 16 + 41 \newline √(x-3)^2 + (y +4)^2 <=9$ what now

#

come on are you kidding me right now? I waited 30 mins for a channel angerysad

dusk horizon
#

Missing a dollar sign?

rancid steppe
#

do i open a new help chat now?

dusk horizon
#

Just try your message again here

leaden wadi
#

Perhaps don't delete the original message. 🤷‍♂️

rancid steppe
#

I am not trolling?!!

leaden wadi
#

They deleted the original message which is why the channel was closed.

rancid steppe
#

${√x^2 -6x +25} + {√y^2 +8y+ 41} <= 9 \newline {√x^2 - 6x + 9 - 9 +25} + {√y^2 + 8y + 16 - 16 + 41}$

jolly parrotBOT
#

Simon James B
Compile Error! Click the errors reaction for more information.
(You may edit your message to recompile.)

rancid steppe
#

why cant i type √

spare lark
#

Its better that you open a new one they're free now

leaden wadi
#

Use \sqrt{}

rancid steppe
#

i am opening a new one

pearl pondBOT
#
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brave sluice
#

are groups of prime order cyclic?

pearl pondBOT
brave sluice
#

or are groups of prime order abelian?

#

i think they are but i'm looking for a theorem in my book

#

or am i misremembering something?

novel apex
#

I know that groups of order p^2 are abelian

#

maybe it is the same for groups of order p

fluid axle
brave sluice
#

thanks

main oxide
#

if you can prove they're cyclic, then you're good cause cyclic groups are already abelian

fluid axle
#

cyclic implies abelian

brave sluice
#

what is the argument?

#

for prime -> cyclic/abelian

#

my book has a chapter on cyclic groups

main oxide
#

you might need to use lagrange's theorem

brave sluice
#

the order of an element divides the order of the group

#

therefore an element other than the identity generates a subgroup the same size as the group

novel apex
#

so every elements can be written as power of other elements

#

then you can conclude

brave sluice
#

oh i found it as a corollary to the theorem of lagrange

#

every group of prime order is cyclic

#

thanks folks 🙏

#

.solved

pearl pondBOT
#
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regal heath
#

are there any videos about homogeneous and non homogeneous recurrence relations with explanations of why the "formulas" work?

pearl pondBOT
#

@regal heath Has your question been resolved?

pearl pondBOT
#

@regal heath Has your question been resolved?

pearl pondBOT
#

@regal heath Has your question been resolved?

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charred lynx
pearl pondBOT
charred lynx
#

idk how to do this

limpid lily
#

I'm not sure exactly what method they want you to use, but one method is to use the fact that the derivative (here, g') is the slope of the original function at that point.

#

So, when x is 3, g'(x) gives you 3, so the slope is 3 there.

charred lynx
#

eah

#

its

#

approximation

#

tangent line approximation

limpid lily
#

Right, so the formula from algebra for the slope is (y0 - y1)/(x0 - x1) or something like that and the slope is 3.

charred lynx
#

Ooooooh yeahhh wait

#

I see

#

i get it now.

#

thx.

#

.close

pearl pondBOT
#
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limpid lily
#

You're welcome.

pearl pondBOT
#
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sharp smelt
#

Determine if it's possible to have a cauchy sequence with an unbounded sub-seqeunce.
\
I was thinking $a_n = \sum_{i=1}^{n} \frac{1}{i}$

jolly parrotBOT
#

math rocks(wai)

west sapphire
#

is that a cauchy sequence?

sharp smelt
#

Isn't it?

#

I see

west sapphire
#

do you know the theorem that (in R or C)
cauchy <==> convergent

sharp smelt
#

yeah it isn't

#

oh

#

I forgot the backward implication

#

oops

#

Thanks

#

.close

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#
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#
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mellow idol
#

hi, i was solving a question on functional equations and to prove the functions injectivity i assumed f(af(0))=f(bf(0)) and then got this implies a^2=b^2. but then this implication would mean f(0)=0 which would make my initial assumption f(0)=f(0) does this make it invalid?

pearl pondBOT
mellow idol
#

<@&286206848099549185>

stable dune
#

you basically just showed that your assumption of f being injective doesnt fail in this regard

pearl pondBOT
#

@mellow idol Has your question been resolved?

mellow idol
#

i mean f(0) = f(0) need not be assumed right

#

i assumed f(af(0))=f(bf(0)) and got that the functions injective but when i use injectivity i also get f(0)=0

#

im asking does f(0)=0 invalidate assuming f(af(0))=f(bf(0)) to prove injectivity

mellow idol
# mellow idol

can someone tell me if my proof is valid or not? cause if it is it trivialises the question

main oxide
#

I don't really see or understand your proof

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#
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harsh nymph
#

Hello can someone give me some resources for prepare for math competition? or some book for proof? I'm currently in high school year 12

sharp smelt
#

For proof , book of proof ( yes, that's the name) is a nice book

harsh nymph
#

is it beginner friendly?

#

like not too advanced concept

sharp smelt
#

For the most part, yes

harsh nymph
#

oh ok i will check it out

pearl pondBOT
#

@harsh nymph Has your question been resolved?

cinder thistle
#

what is the syllabus?

pearl pondBOT
#
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quick star
#

stupid question but percent increase can be both additive and multiplicative?

pure rapids
#

wdym

quick star
#

increase by 20% and then a further 20% can be additive or multiplicative.

additive: 100% + 20% + 20% = 140%
multiplicative: 1 * 1.2 * 1.2 * 100 = 144%

errant fable
#

oh wait

quick star
#

what

#

where am i making a statement?

pure rapids
bitter herald
#

the difference between compounding and simple interest

#

to give you an analogy

#

the multiplicative one "adds on" to the previously applied percentages

#

whilst the additive one is always a linear increase based on the principal amount

#

So yes, percentage increases can be additive or multiplicative, depending on the context and the assumptions made about the base value

pearl pondBOT
#

@quick star Has your question been resolved?

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#
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prisma elk
#

quick question: if z = (1/ i*x )
lim x->0+ arg(z) = ?

pearl pondBOT
#

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ebon burrow
pearl pondBOT
ebon burrow
#

<@&286206848099549185>

regal plume
#

@pearl pond

ebon burrow
#

Hello

#

Pls help

#

<@&286206848099549185>

sacred crest
#

Don’t spam the helpers ping

ebon burrow
#

Ok sorry

#

😦

#

@sacred crest could u help me ig?

pearl pondBOT
#

@ebon burrow Has your question been resolved?

cinder thistle
#

so where did you get till yet?

ebon burrow
#

@cinder thistle

cinder thistle
#

try constructing a square

ebon burrow
#

Ok wait

#

Doin

sacred crest
ebon burrow
#

Like how to proof.

#

Give me some hint please

sacred crest
#

Just try things out

ebon burrow
#

Not working for 3x3

sacred crest
#

How about 5x5 then

ebon burrow
#

Do you know that's 5! Many combinations

#

About 120

#

I'm not to try ot

#

Is there, say any suitable algo for it?

sacred crest
#

Idk, could be. It looks like you’re supposed to figure out such an algorithm on your own though, cause you’ll learn a lot more that way. Unless this is supposed to be easy homework

pearl pondBOT
#

@ebon burrow Has your question been resolved?

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sharp smelt
#

If $(x_n)$ and $(y_n)$ are cauchy seqeunces then prove that $x_n+y_n$ is a cauchy sequence, without using the cauchy criterion or the algebric limit theorm

jolly parrotBOT
#

math rocks(wai)

sharp smelt
#

I'm confused

#

so here I cannot use the defn of a cauchy seqeunce in my proof?

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The proof I had in mind was $\abs{x_n - x} + \abs {y_n -y} = \abs{x_n-x_m + x_m -x} + \abs{y_n - y_m+y_m-y}< 2 \varepsilon \implies \abs{x_n-x_m} + \abs{x_m-x} + \abs{y_n-y_m}+ \abs{y_m-y} < 2\varepsilon$.

jolly parrotBOT
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math rocks(wai)

sharp smelt
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Now as $\abs{x_m-x}$ and $\abs{y_m-y}$ convergre, i replace, both with $\varepsilon/2$, to obtain $\abs{x_n-x_m} + \abs{y_n-y_m} < \varepsilon$

jolly parrotBOT
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math rocks(wai)

sharp smelt
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That would tell us the series is a cauchy seqeunce

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is this fine

pearl pondBOT
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@sharp smelt Has your question been resolved?

sharp smelt
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<@&286206848099549185>

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.close

pearl pondBOT
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pearl pondBOT
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sleek junco
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can someone explain how n^-n come

pearl pondBOT
sleek junco
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at the third equal sign

open rivet
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they are doing $(n+1)^{-n}=\left(n\left(1+\frac1n\right)\right)^{-n}=n^{-n}\left(1+\frac1n\right)^{-n}$

sleek junco
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oh

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disgusting but oh welp

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thx for the help

jolly parrotBOT
sleek junco
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.close

pearl pondBOT
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pearl pondBOT
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quick star
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,, a \frac 1b

pearl pondBOT
jolly parrotBOT
quick star
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is this mixed fraction or product?

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i know something like $2 \frac 12$ is mixed fraction but like is it the same with variables?

jolly parrotBOT
safe prairie
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thats just a/b

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thats just a normal fraction

quick star
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why is it not mixed fraction?

safe prairie
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but if you insist it be written that way yeah its mixed

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for mixed fraction you see them as 2 + 1/2

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for variables youd just multiply any adjacent thing

quick star
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but that's not notation for mixed fraction, is it

jolly parrotBOT
safe prairie
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ofc 2 + 1/2 is a wrong notation

safe prairie
quick star
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depends on context?

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my teacher wrote that and expected us to know it's a mixed fraction

safe prairie
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a + 1/b?

safe prairie
quick star
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yeah well they wanted me to interpret it that way

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anyway thanks

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i won't make a big deal out of something trivial

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😭

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.close

pearl pondBOT
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pearl pondBOT
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rancid steppe
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$ax - bx + ax^2 - bx^2$

pearl pondBOT
jolly parrotBOT
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Simon James B

rancid steppe
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I did $x(a-b) + x^2(a-b) \newline (a-b)(x + x^2)$

jolly parrotBOT
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Simon James B

rancid steppe
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but it seems that this was not right

open rivet
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it should be correct

warm copper
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x(x+1)(a-b)

open rivet
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ah, yes

rancid steppe
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ah i see it

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$x(1+x)(a-b)$

jolly parrotBOT
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Simon James B