#help-27

1 messages · Page 428 of 1

ocean haven
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nah

shy osprey
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-# what are you trying

ocean haven
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,w 1/30 (-60 x - 5 cos(3 x) - 15 cos(4 x) - 3 cos(5 x) - 120 sin(x) + 35 sin(3 x) + 15 sin(4 x) + 3 sin(5 x)), x = pi

ocean haven
shy osprey
#

-# whats the Qsn

ocean haven
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,w 16/3 + pi

ocean haven
#

@shy osprey

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i kill

shy osprey
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.pin

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ocean haven
#

.close

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#
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shy osprey
#

-# ??

#

-# solved?

ocean haven
#

dont try its wrong

shy osprey
shy osprey
ocean haven
#

ikr

#

ty anyways

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sand mesa
#

I would like to learn more maths stuff but I don't know what to do.

upper urchin
#

how to solve part b, pls help

brave plaza
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trail eagle
shy osprey
#

lol try another one @upper urchin

sand mesa
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sorry

upper urchin
sand mesa
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im going to specify

upper urchin
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im new to the server

shy osprey
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flint talon
shy osprey
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Shit

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Sorry about that

sand mesa
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i want to learn more, i'm in year 8 (uk) and i want to know more things

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just in general

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because i'm finding maths lessons quite boring because i already know

trail eagle
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Have you looked into the curriculum for years above you? It might give you an idea of things to look into,

sand mesa
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we don't have access to upper years

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like

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looking at the curriculum

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well

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on the website it gives vague things such as 'trigonometry', 'calculus' etc.

trail eagle
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The specific curriculum may not be available like published from your school, but there's lots of information online about what a typical year 9+ learns

sand mesa
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i'll try looking into that

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but

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what would you advise?

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specifically

sand mesa
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i have a khan academy account (i learnt functions for fun)

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would that be a good thing

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to user

sand mesa
trail eagle
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Yes, that's a good ressource for learning

sand mesa
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ok

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so i'll read through it and learn it on khan academy

trail eagle
#

Yes, they probably have a nice progression on there

sand mesa
#

It's quite a fun and engaging format, so yes

#

ok then

#

.close

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trail eagle
sand mesa
#

ok

#

thanks

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trail eagle
#

<@&268886789983436800>

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orchid oriole
#

Hey guys i don't need much help i just need clearance on Why did you distribute the cosine across the brackets when I could provide the derivative inside a bracket? I'm watching a video and studying it, and it explains how to distribute the cosine instead of providing the derivative. So im wondering is its possible to just provide the derivative since its already there just add (-)?
Also, is there another method besides the difference between two squares? Just wondering because i don't wanna be stuck in solving with 1 way its like having to memorize the questions more than understanding it

small geyser
#

,rccw

woven radishBOT
orchid oriole
#

Sorry if my handwriting is cursed but thats how it usually is when i write fast

trail eagle
#

I don't know if that's what you mean, but could write it as $$\int (1+\sin(x))\cos(x) \dd{x} = \int (1+\sin(x)) \cdot (1+\sin(x))' \dd{x} = \frac{(1+\sin(x))^2}{2} + C.$$

woven radishBOT
#

Azyrashacorki

orchid oriole
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I see, now thats easier than the way he provided it to me

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I thought of it but didnt know if i could use it

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And about the 3rd step where i Solve by the difference of two squares is there another way i could use?

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Instead of (1-sinx)(1+sinx). Cosx dx/1-sinx?

narrow plank
orchid oriole
narrow plank
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if there is a simpler way to do it, i don't know about it lol

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i wish i knew everything - that'd be cool.

But I think cancelling is probably the simplest way.

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my general approach is get f(sinx) * cos(x) dx as an integrand to prep a u-sub

orchid oriole
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I mean hey, you're the boss here you know more than me so i guess imma leave it as its

narrow plank
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i wouldn't give myself the title of "boss", but i appreciate it!

orchid oriole
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Alright i guess thats it for me i just needed some clearance of other ways to solve that, thanks yall much appreciated you can close this because idk how

narrow plank
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you can type .close in the channel

trail eagle
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I think that's pretty much the clearest way forwards. The only other way I can think of would be to start off with u = 1-sin(x) at the very first line, but the process is not very clean.

orchid oriole
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Thanks though i will just use Difference between two squares whenever i had chance to

#

.Close

narrow plank
orchid oriole
#

.close

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unborn depot
#

hello! ive done this question and ive gotten a 25 degree. can someone double check if the ans is 25?

last parrot
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Can you show your working?

devout snowBOT
#

@unborn depot Has your question been resolved?

unborn depot
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one moment

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let me get it rq

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sorry this is so messy

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unborn depot
#

<@&286206848099549185>

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fresh meteor
#

yow

unborn depot
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can someone double check my work?

fresh meteor
#

My answer is the same as yours, $$\angle A \approx \arctan(0.466) \approx 24.98^\circ \approx 25^\circ$$

woven radishBOT
#

ShiroSharata

unborn depot
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thank u so much

#

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sullen karma
devout snowBOT
sullen karma
#

Sorry forgot how to rotate

#

But could I please get help started on 3a could I get a tutorial on how to do it please

woven radishBOT
rotund verge
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Oooo thank god

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Ok so for the value of k

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We need to find the sum of all probabilities

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And they will obviously equal 1

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Cause probabillities

sullen karma
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Yes alright

rotund verge
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We expresses this as

sullen karma
#

So would it’s be k+k+…

rotund verge
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Um the mathmaticall

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God i cant find the sign

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Ok your aware of stigma right?

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Or just sum

sullen karma
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Yes

rotund verge
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Ok so stigma p( X = X ) =1

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So basically at

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X =0

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Height is k

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X = 1

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Height is k2

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X = 2
Height is k3

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But x=3
Height is k4

sullen karma
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Hold on what

rotund verge
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Wait no

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I mentk4

sullen karma
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Yeah alright

rotund verge
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So we add all of these

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To get k10

sullen karma
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Yes

rotund verge
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Which can be represented as 1/10

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Which is basically

sullen karma
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Yes

rotund verge
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0.1

sullen karma
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So the answer is 0.1?

rotund verge
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No

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In a probability histogram the area of each bar represent the probabilith

sullen karma
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Ohhh alright

rotund verge
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The width kf each bar is 1unit

sullen karma
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Yes

rotund verge
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(0 to 1 , 1 to 2 etc )

sullen karma
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Wait hold on

rotund verge
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Ya

sullen karma
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How is k10 = 0.1

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??

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Did u do k10 = 1

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K =1/10

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??

rotund verge
sullen karma
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Ah alright

rotund verge
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1/10

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Probability

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Can be 1

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Maximum so we use that

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Got it?

sullen karma
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Yes

rotund verge
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And the height is used for probability

sullen karma
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Yes

rotund verge
#

For x 0 to 1
Height is k

From x 1 to 2
Height is k2

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And so on

sullen karma
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Yes

rotund verge
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We can conclude

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K+ 2k +3k + 2k + 1k = 1

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8k = 1 as i mentioned

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Before

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Oh wait

sullen karma
rotund verge
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You only want help for ka

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I mean

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3a

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Not all

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😭😭😭😭

sullen karma
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I’m confused abit oh ye I just want a but it’s fine

rotund verge
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I was explaining all and I got confused why so long for question

sullen karma
#

So what’s the answer for a abit confused

rotund verge
sullen karma
rotund verge
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Wait let me look at the graph again

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Oh wait no Iwas solving a now i did it in a weird order cause I looked at the sideways view

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Ok

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So

rotund verge
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8k = 1

sullen karma
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So for a the answer is 1/8??

rotund verge
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So k = 1/8

rotund verge
sullen karma
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That’s what I thought but my textbook says it’s 3/8

rotund verge
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Wait waaa

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Wait for a?

sullen karma
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Yes

rotund verge
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1k 3k 3k 1k

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8k

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8k=1

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K=1/8

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Maybe my math is wrong or smth?

sullen karma
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I think the textbook just has a mistake

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Cause ur working makes sense

rotund verge
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Hm

sullen karma
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Ty for ur help though I appreciate it sm 🙂

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😄

rotund verge
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Ya my textbook does the same thing it said do until 2decimal point but the textbook does until 3 and rounds it off i got 1number off every time and I was so angry

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😭😭😭😭😭

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But ya sir gave me full makrs

sullen karma
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😭😭

rotund verge
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Later when I talked with him

rotund verge
# sullen karma 😄

Welcome also kinda sorry for extending this small easy answer into such a long thing i kinda got confused which question was which and went ahead solving them all

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😅

sullen karma
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Enjoy the rest of ur day / night 🙂

rotund verge
#

Hm thanks you too

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tidal relic
#

pls tell a shot trick to solve this

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rapid pewter
#

The formula for compound interest is (\operatorname{CI} = P \cdot \left(1 + \frac{r}{n} \right)^{tn}) where (P) is the principal, here (P=10000), (r) is the annual interest rate, here (r=0.06), (n) is the compounding frequency, in your case (n=1) and (t) is the amount of time that you are compounding for, in this case (t=3)

woven radishBOT
#

Ryan [She/Her] (TCC)

rapid pewter
#

Do you understand how I put the values into the formula from the board or are there any steps you would wish for me to explain?

#

@tidal relic

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#

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tidal relic
#

Thank you i got it

rapid pewter
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lost laurel
#

Part(c)
Define $A_n$ to be that sequence consisting of $f_{n_{k}}(x_1),f_{n_k}(x_2) \dots f_{n_{k}}(x_{m})$ where the seqeunce are intereweaved in that order

woven radishBOT
sand quarry
lost laurel
sand quarry
#

Well not for all x thats for sure

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Cant you use cantor's

lost laurel
#

But first I need to come up with a sequence

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Define $A_n(x)$ to be that sequence consisting of $f{n_{k}}(x),f{n_k}(x) \dots f{n{k}}(x)$ where the seqeunce are intereweaved in that order

woven radishBOT
sand quarry
#

Cuz like

lost laurel
#

Lemme think a bit more then I suppose, this is a problm worth thinking about

#

.close

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shy osprey
#

Whats the maximum radius of a semicircle which can be contained in a square of unit length

shy osprey
#

-# ping me if any idea

shy osprey
#

Nothing js confused

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<@&286206848099549185>

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oh shit

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15mins

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sorry

green crypt
#

its alright

shy osprey
#

it could be inclined asw?

finite fable
shy osprey
#

you cant

finite fable
#

umm. why not?

shy osprey
#

it would go out of the sqaure

finite fable
#

hmm

thick lotus
#

you do have an upper bound

finite fable
#

R^2 = 2a^2 + 2R^2 -4aR?

finite fable
torpid sun
finite fable
#

i mean algebra

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R^2 + R^2 = 2R^2 and it should 2ar instead of 2r

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@shy osprey what do you think>

shy osprey
#

i didnt really understand how you got this😭

#

am bad at geometry sry

finite fable
finite fable
shy osprey
finite fable
#

and you said we cannot have diagonal

shy osprey
#

wouldnt the diameter be 45 degree with the edges

finite fable
#

congruency

shy osprey
#

okay go on

torpid sun
# finite fable

(it's intuitively easy to see how that would be the figure with max radius but how do u prove that catthink )

finite fable
#

i mean it should be somewhere from here only

shy osprey
finite fable
#

lemme think with my small mind

finite fable
#

angles then equal

torpid sun
shy osprey
#

okay and how will that explain 45 degrre statement

shy osprey
shy osprey
shy osprey
#

not sure tho i maybe wrong

finite fable
#

we constructed a semi-circle with a radius greater than 0.5

shy osprey
finite fable
#

so half a side of a square is certainly not the maximum radius

torpid sun
thick lotus
finite fable
#

but lemme think with my small mind again

shy osprey
#

-# geo is not my strong point sry

finite fable
#

i saw its application once

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i cant remember it

shy osprey
#

Tysm!!

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.close

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#
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finite fable
#

explain bro

thick lotus
shy osprey
shy osprey
thick lotus
torpid sun
#

I got root2/(root2+1)

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which ig on rationalising gives 2-sqrt2

shy osprey
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elder bobcat
#

Hii guys!! I'm just confused why this is true

elder bobcat
#

Is that even eligible 😭

lunar harbor
#

zoomed in version:

lunar harbor
elder bobcat
#

Tqq

sand quarry
#

For continuous functions you can do [
\lim_{x\to a} f(g(x)) = f(\lim_{x\to a}g(x))
]

woven radishBOT
elder bobcat
#

Mhm

sand quarry
elder bobcat
sand quarry
#

Try to apply it to your problem

elder bobcat
#

How

unique monolith
elder bobcat
#

I don't know what I'm finding

trail eagle
#

Compute the limit at infinity of what's inside the logarithm.

unique monolith
deft tapir
#

If we have something like lim (x+4)² we can find the lim of x+4 then square that

trail eagle
deft tapir
#

So if you have a composite function, you can calculate the limit of the inner function, and then plug that into your function

elder bobcat
#

As t tends to invite, what would Ln (t+1) tend to. I can't picture it

deft tapir
#

Then you calculate ln(+inf)

elder bobcat
#

I see

deft tapir
#

(for the sake of accuracy, it becomes lim ln(x) as x approaches +inf)

elder bobcat
#

Bur no

#

Hmmm

#

Okay so

deft tapir
#

The idea always remains that you calculate the inside part, then plug that into the outer function

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Try to apply that to your problem

elder bobcat
#

Okok

#

Would the numerator tend to infinity and also the denominator?

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Omg I feel like I don't know enough

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😭

deft tapir
#

When you have a fraction of two polynomials

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The limit as x approaches ±inf follows the behavior of the largest exponent's term

elder bobcat
#

I see, 2?

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Like 2²

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The exponent of t or

deft tapir
#

So something like $$ \frac{5x^2 + 6x -2}{x^7 + x^6 + 8x^3 - x} $$ can simplify to just $$ \frac {5x^2}{x^7}$$

elder bobcat
#

Oh I see why 2 thou

woven radishBOT
#

ScoobySnacks

elder bobcat
#

Ahh okok

deft tapir
#

I suggest simplifying your numerator and denominator first

elder bobcat
#

So here would it be 2t²/t

Or would I need to simply first

deft tapir
#

Although remember, the highest exponent term by itself is sufficient

deft tapir
elder bobcat
#

Hm would it be 4t⁴/t⁴

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Sorry for the late reply, had to take care of something rq

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Hmm then u cancel out to get 4

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Okok I get it tqqqqqqq

#

Sm

#

I didn't know the polynomial rule but thinking about it seems intuitive, I didn't catch on 😭

trail eagle
#

In general you can always do this to get a simpler limit to analyse. It stems from the fact that you can divide the numerator and denominator by the highest power of your variable and make terms like 1/x^n vanish in the limit.

elder bobcat
#

Hm I see I see

#

That makes sense

trail eagle
#

And as for the original thing about bringing the limit inside the logarithm, this is a property of continuous functions in particular.

elder bobcat
trail eagle
#

Yes

deft tapir
elder bobcat
#

Hm oh like finding out the limit for t+1 first

elder bobcat
#

If it approaches 0, I would only see the constants?

deft tapir
#

You just sub the t values

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And check what you get

elder bobcat
#

Hm okok

#

Thanks

#

Everyone

#

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deft tapir
#

Was a pleasure! Keep mathing

elder bobcat
#

Lowky kinda fun

lilac moat
#

.reopen

devout snowBOT
lilac moat
#

also

#

though this is not necessary in this particular example

#

a technique that is useful sometimes for limits at infinity is

#

to make a substitution t=1/u, then t->+infinity is interchangeable with u->0+. if that confuses you, nevermind it, but it can be helpful

#

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elder bobcat
#

And becomes insignificant

#

No

#

I'm so stupid

#

I read it wrong

#

give me a sec

lilac moat
#

simple example:

lilac moat
#

lim t->+infinity ln(t)= lim u->0+ ln(1/u)

deft tapir
#

I'm not sure that quite helps there tho

lilac moat
#

i use it mainly for inequalities

#

squeeze theorem

elder bobcat
lilac moat
#

okay nm if it confuses you, its not necessary!

#

maybe youll get it later :)

deft tapir
elder bobcat
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inland carbon
#

P and Q are polynomials such that deg P<= deg Q - 2, and Q has no real roots\
In the first part, I had to show that $\int_{-\infty}^{+\infty} \frac{dt}{(t-z)^k}$ equals 0 if $k\geq 2$ and $i\pi \epsilon(z)$ where $\epsilon$ is the sign of the imaginary part of z when k=1

Then I had to show $$\int_{\mathbb{R}} P/Q = i \pi \sum a_k \epsilon(z_k)$$ where the sum is over the roots of Q, and $a_k$ is the coefficient in front of $(x-z_k)^{-1}$ in the partial fraction decomposition. \

Then I need to show that in the case where P and Q are real this is in fact equal to $$2i\pi \sum_{Im(z_k) >0} a_k$$ but I don't see why the $a_k$ are necessarily purely imaginary

woven radishBOT
#

bloubbloub

inland carbon
#

Also I don't know any complex analysis

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sullen island
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sullen island
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.reopen

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cyan scarab
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cyan scarab
#

=))

lean crater
last parrot
sand quarry
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cyan scarab
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cyan scarab
#

=))

small geyser
#

!occupied. and you have a forum post ongoing, so please wait for help there.

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last parrot
last parrot
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last parrot
#

Biết xài mod ko

#

Môđun

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cyan scarab
last parrot
cyan scarab
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ok

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orchid oriole
#

Hi, im back again my exam is in 2-3h and i finished most of integration but there's only 1 thing that i struggle with no matter how i revise or how i solve equation because except its hard to remember i don't know where and when and how to use these laws

orchid oriole
#

Lets say i know a bit about cos2x=1-2sin²x and cos2x=2cos²x-1 since its all about if theres cos or sin next to it we use them To provide a derivative within an arc but the rest? Idk ig

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fresh meteor
#

!show

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#

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

orchid oriole
#

I mean i will provide with what i struggle with as in equations if thats what u mean

#

Q.no7 is not that hard but its the laws that i mentioned is what making it confusing because idk why he used that instead of other ways same for Q.No4 when i couldve used something else i think?

fresh meteor
#

Actually, I meant, show how far you've tried to do it, but btw I've tried and it turns out I don't really understand it either ahahaha
Let someone else help you

#

<@&286206848099549185>

orchid oriole
#

Its the start that needs these laws that makes me confused like, when how where do i use them? Isnt there other ways to solve them? If so why isnt it provided such as power reduction formula

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orchid oriole
#

I gotta go now cya yall

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rain coral
#

what is up witb this q

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dire thistle
#

Hi, can anyone provide the solution manual for Applied Numerical Methods with MATLAB for Engineers and Scientists (5th Edition) by Steven C. Chapra?
I really need it for my studies. Any help would be greatly appreciated!

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supple knot
rain coral
#

like

#

i solve it

#

attempt i mean

#

and it jst

#

idk

supple knot
#

Uh huh

rain coral
#

it jst gets too long and it doesnt work out

#

like oaky

#

first get z in terms of w

#

put it into u+vi

#

real=x

#

imaginary=y

#

plug into the circle eq

#

and jst

#

its too long

supple knot
# rain coral real=x

Mistake here probably. Easier to just leave z in terms of complex. Do you know how to write equation of a circle in modulus form?

#

Like |z| = 1 is a circle of radius 1 is the same as x^2 + y^2 = 1

supple knot
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#

@rain coral Has your question been resolved?

rain coral
#

what

#

wld it be in this case

supple knot
#

Find z0 and r

rain coral
#

man thats so much easier

#

man

#

ok i see

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cyan barn
#

hello i want help in

devout snowBOT
#
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
cyan barn
#

1

#

should i do the sign of a then start?

cyan barn
#

could anyone help me?

#

please in finding the integral

lament frigate
#

does the form of these look familar

#

perhaps in the form of certain derivatives?

cyan barn
#

no

lament frigate
#

(hint, inverse trig functions)

cyan barn
#

arctan?

lament frigate
#

,w derivative of arctan(x)

woven radishBOT
lament frigate
#

compare with b)

cyan barn
#

so if i took a =1 its her

lament frigate
#

and what if a ISN'T one?

cyan barn
#

but like should i do that if its zero its false and all the sign or i what

lament frigate
#

(If a is 0 then the result is just reverse power rule)

cyan barn
#

sorry ik i am dump

lament frigate
#

(hint: u-sub)

#

?

cyan barn
#

sorry didnt catch it well so i need to take another value variable changement first) right?

lament frigate
#

if a isn't one then yes, you should use a u-sub

#

You know which sub to preform?

cyan barn
#

yes if its not 1 or 0

#

no

#

tbh

#

but

lament frigate
#

you know u-sub, yes?

cyan barn
#

yes

#

variable changement

#

sould i take if its not 1 or 0 1 on the racine of a

#

??

#

the x

lament frigate
#

Well wouldn't it be cool, even if a wasn't one, we could factor out 1/a^2 from the integral and make it 1?

cyan barn
#

can i send u a small solution and tell me what do you think abt it?

lament frigate
#

ok

cyan barn
#

should i delet the cases ?? is it right?

lament frigate
#

we were talking about part b,

cyan barn
#

ahh i taught its a

#

sorry

lament frigate
#

It's ok

#

do you get what I was saying about it tho?

cyan barn
#

yeah but what should i take as u..sub

lament frigate
#

Well, we want to factor out the constant right?

cyan barn
#

yeah

lament frigate
#

so it's just 1 and it's arctan right

cyan barn
#

yeah sir

#

if its 0 its normal

lament frigate
#

we would need u to have a factor of a

#

so we could factor a

#

right?

cyan barn
#

yes

lament frigate
#

So what do you think of the sub u=ax

cyan barn
#

wait let me think abt it for a sec

#

ok thank u soo much

#

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compact kiln
#

find the equation of the tangent circle that is normal to the line

compact kiln
#

I need help with this task guys

#

<@&286206848099549185>

dull parrot
#

then substiute it into the other equation

#

and solve for x

torpid sun
#

is that supposed to be x^2+y^2+2x+4y+7?

#

because you've written x^2-y^2

#

which would not give a circle

#

is the question to find the equation of the tangent to the circle [as given in question] such that it is perpendicular to 3x-4y=0

dull parrot
#

I didn't realise it was x^2 - y^2

torpid sun
#

Mhm, I think it's most likely just a typo

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compact kiln
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compact kiln
#

she could do a typo i guess

#

I think this is a good solution, no?

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elder bobcat
#

I'm stuckk

devout snowBOT
elder bobcat
#

This is what I've done so far

#

Amd im not sure if I've made a mistaje

#

*mistake

uncut crow
elder bobcat
willow helm
elder bobcat
#

I see where

willow helm
#

oh I was making a joke on mistaje 🙂

elder bobcat
#

I dont have any humour in me rn the work is draining me

uncut crow
elder bobcat
#

@helper ty, any help would be appreciated

#

Opf

#

<@&286206848099549185>

last parrot
#

Isn't the derivative of coshy is sech^2x

#

What is sec^2hy here

harsh stream
last parrot
#

Similarly to coshy = sqrt(1+sin^2h) it must be sqrt(1+sinh^2)

harsh stream
#

Derivative of cosh is sinh

#

Oh ok

#

U confused me with the sech^2y

#

😭

elder bobcat
#

Let me see

#

Oof yea soryy

#

Let me change it

last parrot
#

Ye

simple grotto
#

By the way, sech is one function not secant if h?

uncut crow
#

hyperbolic secant

elder bobcat
#

Ye

simple grotto
#

Just making sure you are doing the right thing. X E.

#

Carry on. X E.

elder bobcat
#

Kkkk

#

I don't know here to go from here 😭

last parrot
#

What is X.E.

last parrot
elder bobcat
elder bobcat
#

Oh

#

I see

#

😭

#

Sighhh

#

Omg

#

Thanks guys

#

I was js being really stupid

#

Kk

#

Thanks again

#

.close

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granite island
#

can i pls have a hint for the problem i legit don't know where to start

granite island
#

maybe we can represent the star as a function instead

#

not really usefull tho

supple knot
#

Try replacing a with b * a

granite island
#

ok

supple knot
#

And maybe another substitution if that doesn't complete the proof. The only thing you have is closure so you have to use it creatively

granite island
#

ok thx

granite island
#

does that mean a=b*a?

supple knot
#

No?

granite island
#

or is it let a=b*a for some a and some b

supple knot
#

Also no

granite island
#

oh

supple knot
granite island
#

oh

granite island
uncut crow
#

bad way to express that

granite island
#

ok

#

so how should i express it?

uncut crow
#

well you shouldn’t write “let ab = a” anywhere

granite island
#

yea i know

#

just kinda confused abotu what he said

uncut crow
#

one way to think of it would be to imagine that the given condition was (c*d)*c = d for all c,d in S. then you are given arbitrary a and b and you want to prove a*(b*a) = b

granite island
#

yes

uncut crow
#

then ‘letting c = something’ makes more sense

granite island
#

ok

uncut crow
#

so you can pick some c and d (in terms of a and b) and get a true statement. hopefully one that helps you prove the equality that is requested if you pick them well

granite island
#

ok

#

so i got (ab)(cd)=a(b*(c*d))

#

wait the stars are gone oops

#

like i want to show taht

uncut crow
#

\*

supple knot
#

I don't understand how you have 4 variables now

granite island
#

sub a= c * d

uncut crow
#

there should only be a’s and b’s in the equality ‘derived’ from putting things into (c*d)*c = d

granite island
#

what

#

yea i don't understnad pls elaborate more

uncut crow
#

you want to set c and d equal to something (in terms of a and b) so that a*(b*a) = b pops out of (c*d)*c = d

#

put c = something that only has a’s and b’s

#

same with d

#

replacing c and d in the equation will give you something with only a’s and b’s

granite island
#

ok

#

so let c= a * b

#

d=b * a

#

wait what

uncut crow
#

that is a legal thing you can do

granite island
#

ok

uncut crow
#

it may or may not be helpful but that is the idea

granite island
#

yea uh how is this usefull

uncut crow
#

maybe your choice was not helpful. you may need something else

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drowsy parcel
#

can anyone teach me every trigonometry basics that can be used in linear algebra

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drowsy parcel
#

.close

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fickle moon
#

is all the work in this done correctly??

devout snowBOT
glossy dew
#

if $v'(t) = \vec{a}(t)$ is a reasonable enough expression to the teacher

woven radishBOT
glossy dew
#

hmm that's okay then i guess

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warm aspen
#

can someone explain me path integrals,

devout snowBOT
placid minnow
#

in context to a problem or just in general

#

like are you talking about the feynman path integral or something

warm aspen
sand quarry
#

Probably line integrals

#

In context of multivariatr calculus

#

Oh ok nvm

#

I feel like this is better asked in a physics server

placid minnow
#

well as you know things dont have a definite position in the quantum world really

warm aspen
#

yes

sand quarry
#

I mean usually the stepping stone idea is the double slit experiment

placid minnow
#

yeah

#

actually thats probably the experiment to read up on for this

#

im not that qualified for this

warm aspen
warm aspen
sand quarry
#

If you can formulate it into a mathematical problem sure

#

As it stands your question is not obviously of that sort

#

But like

#

Conceptually speaking

#

If you want to calculate the probability of an electron or particle or whatever going from point A to B, you have to sum up the probabilities of it taking every single conceivable path in the universe

sand quarry
#

,, \vb P(A) = \sum_n \vb P(A\cap B_n)

woven radishBOT
sand quarry
#

That's how I see it

warm aspen
#

when you think about it like that, while doing the summing up, in a specific case abcdef, if the particle moves zig zag for like 500km and THEN reaches point b,

do you not have a problem with THAT abcdef case being a total summation of all OTHER possible paths being made into that abcdef?
why do you only have a problem with the real path which the electron takes and not have a problem with the other infinitely imaginary paths it would take according to you

sand quarry
#

It is its own path

warm aspen
sand quarry
#

It is

warm aspen
#

it's just a unique path independent to all other paths the electron could take

sand quarry
warm aspen
sand quarry
#

If you make an electron go through double slits, where it appears on the other side is dictated by a probability function because it is not a deterministic process and cannot be known a priori

#

Feynman realised that empty space can be thought of as an infinite number of slits, which is why it ties back to your original statement

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#

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smoky gyro
#

im having trouble with finding the bounds for theta

i arrived that the inequality r<=tan(theta)sec(theta) from letting x =rcos y=rsin

and then solving tansec =1 we get that sin(theta) = sqrt(5) - 1 / 2

so theta = arcsin ( sqrt5) -1 / 2 ) but this is only one of bounds for theta and im not sure how to find out the other one

sand quarry
smoky gyro
#

yes golden ratio

sand quarry
#

If so I think thats correct

smoky gyro
#

but thats only one bound for theta

#

how can i find the other one

smoky gyro
#

what

sand quarry
#

Anyway for the other angle, try to think of where the parabola in y >= x^2 intersects with your circle

flint talon
faint gorge
#

did you try to draw the region vro

smoky gyro
#

nah

#

i was never good at art

#

i js rawdog it w algebra basically

faint gorge
#

do both

#

you dont need to be an artist

#

it's just for reference so you understand the algebra

smoky gyro
#

polar stuff is messy here isnt it

#

like the other theta bound isnt just +- theta right that would be wrong do we subtract pi for the other bound

#

(brb dinner)

devout snowBOT
#

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faint gorge
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smoky gyro
devout snowBOT
smoky gyro
faint gorge
#

yes

#

So you can just subtract your angle from pi

smoky gyro
smoky gyro
faint gorge
#

Well if you draw it, you will realize that the angle is mirrored/reflected at the y-axis

#

That's all, so yeah no symmetry with the x-axis

smoky gyro
#

hmm i see

#

my doubts is solved

#

.close

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faint gorge
#

🔡

sand quarry
smoky gyro
#

thats true

#

my doubts is unsolved

#

.reopen

devout snowBOT
sand quarry
#

its not going to be one integral

#

in polar

smoky gyro
#

hmmmm

#

how do i construct

sand quarry
#

try to like trace the rays as you sweep the angle

#

like it will hit different boundaries

#

which will need different integrands

smoky gyro
#

hmmm

sand quarry
#

yes so there are three 'phases'

#

the green, red, and black

smoky gyro
faint gorge
#

you can formulate black and green into one integral

smoky gyro
#

is because they are symmetric

#

so if we have small theta our ray will hit the parabola

#

if our ray is like in the middle we hit the circle

#

and if theta big close to pi then we hit the parabola again

devout snowBOT
#

@smoky gyro Has your question been resolved?

faint gorge
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sour rampart
#

Is anybody there from class 10th cbse i need some tips..

jade pecan
#

!da2a

devout snowBOT
#

Asking the actual question right away is more likely to get responses.

Asking "Can I ask...?" or "Does anyone know about...?" doesn't give people enough information to decide whether they can help, and answering can feel like a promise to help with the actual question, which they might find themselves unable to.

jade pecan
sour rampart
#

Im new to this server is dont quite understood what u said..

jade pecan
sour rampart
#

Ooh

jade pecan
#

if u have specific questions, use the help channels

sour rampart
#

Ok thx

#

Thx

daring basin
#
  1. If a ≡ b (mod n), show that a^n ≡ b^n (mod n^2). Is the converse true?
    Solve this anyone
    Without binomial theorem
devout snowBOT
daring basin
#

Aahh ok

flint talon
#

does that mean there's no question here blk_excuseme

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long trout
#

This is a problem that I thought of, so there might be some inconsistencies. Let S be another sequence that is permutation of the sequence: 1,2,3,…,n. In each move, one can chooses a consecutive subsequence of the previous sequence (initial one being S), and either performs a reversal within the subsequence (flips the order of elements in the subsequence), or a transposition of the subsequence (moves the subsequence around within the sequence). Out of all possible S, what is the largest minimum number of moves to permute from S back to the sequence: 1,2,3…,n ? Ik this may sound confusing, so feel free to ask for clarifications and examples of how it works

placid minnow
#

for operation 2, is it "cut a block and paste it anywhere else" (one block moves), or "swap two adjacent blocks" (the stricter genome-rearrangement definition)? these will give different answers

placid minnow
#

and for each move it is either a reversal or a block move and i can choose right

placid minnow
#

and if i reverse entire sequence that still only costs 1?

#

meaning it costs 1 per move regardless of block length?

placid minnow
#

and you want max_s min(moves to sort S) as a function of n

#

which is just the worst case starting perm

long trout
finite briar
#

supremum esque?

placid minnow
#

so a single reversal can eliminate at most 2 breakpoints, which happens if the elements at the ends of the flipped segment manage to plug the gaps perfectly in their new orientations

#

and for second way to get rid of breakpoints a block move involves cutting the sequence at 3 places and rejoining them, so a transposition can eliminate at most 3 breakpoints

#

so upper limit is going to be using transposition

#

cause if you think about it if a permutation
$S$ has
$b(S)$ breakpoints, and the best possible move removes 3 breakpoints, then the minimum number of moves
$d(S)$ must satisfy:

$d(S) \geq \frac{b(S)}{3}$

woven radishBOT
#

thecrumbeler2

placid minnow
#

so this suggests the number of breakpoints is approximately
$n$ and max distance grows linearly

woven radishBOT
#

thecrumbeler2

placid minnow
#

because we know for a permutation of length
$n$, the maximum number of moves
$D(n)$ required to sort it is:

$D(n) \approx \lceil \frac{n+1}{2} \rceil \text{ or slightly lower depending on the mix of moves.}$

woven radishBOT
#

thecrumbeler2

placid minnow
#

but we are dealing with specifically the combination of reversals and transpositions

#

so if only transpositions were allowed, the maximum distance is
$\lfloor \frac{n+1}{2} \rfloor$

woven radishBOT
#

thecrumbeler2

placid minnow
#

If only reversals were allowed, then the maximum distance is just
$n-1$.

woven radishBOT
#

thecrumbeler2

placid minnow
#

with both the transposition is dominant, which is what i said before

#

and at this point idk the right constant

long trout
#

Oh ok, so it’s better to take transpositions rather than reversals

placid minnow
#

yeah

#

after some research the worst case after a lot of debate seems to be n/2

#

so ill just go with that

#

since even though a transposition can remove 3 breakpoints, it is impossible to find a move that removes 3 breakpoints in every single step for the most difficult permutations. Most moves will only remove 2 or 1

long trout
placid minnow
#

and just thinking about this in small $n$:

woven radishBOT
#

thecrumbeler2

placid minnow
#

$n=2$: Max moves = 1 (e.g.,
$(2, 1)$ needs 1 reversal).

woven radishBOT
#

thecrumbeler2

placid minnow
#

$n=3$: Max moves = 1 (e.g.,
$(3, 2, 1)$ needs 1 reversal).

woven radishBOT
#

thecrumbeler2

placid minnow
#

$n=4$: Max moves = 2.

woven radishBOT
#

thecrumbeler2

placid minnow
#

and $n=10$: Max moves is usually around 5 or 6.

woven radishBOT
#

thecrumbeler2

placid minnow
#

so we already established that for a sequence of length
$n$, the maximum number of moves (the diameter) is approximately: $f(n) \approx \frac{n}{2}$

woven radishBOT
#

thecrumbeler2

placid minnow
#

But going more precisely, for large
$n$, it is bounded by: $\frac{n+1}{3} \leq \text{Max Moves} \leq \frac{n}{2}$

woven radishBOT
#

thecrumbeler2

placid minnow
#

(if you remember what i said before)

#

which is my answer

#

and the most difficult permutations to sort are those that are interleaved, like
$(2, 4, 6, \dots, 1, 3, 5, \dots)$, because they maximize the number of breakpoints that cannot be fixed simultaneously by a single move

woven radishBOT
#

thecrumbeler2

placid minnow
long trout
#

.close

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mystic arrow
#

For this, I’m not too sure on whats happening on the line i’ve underline.

Is it taking n^3 -(n-1)^3 and then adding the (n-1)^3 to both sides? And is the section above displaying that for when you substitute (n-x) in as x approaches n the values follow a progression downwards?

arctic yarrow
#

$n^3 - 1 = \sum_{k=1}^n (k^3 - (k-1)^3)$

woven radishBOT
#

Lin Xia

mystic arrow
arctic yarrow
#

from Newton formula we have $(k^3 - (k-1)^3) = 3k^2 - 3k + 1$, for all $k>0$

woven radishBOT
#

Lin Xia

arctic yarrow
#

I dont know if that is what you asked

mystic arrow
arctic yarrow
arctic yarrow
woven radishBOT
#

Lin Xia

mystic arrow
#

Ohh okay, thank you for your help

#

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sinful sand
#

i need help

devout snowBOT
sinful sand
#

so

#

about infos k is parallel to l

#

what is the degree of showed with ? symbol

untold ravine
#

maybe it helps to extend the line l till it intersects the line below

lethal wraith
#

try tracing this line which is also parallel to k (ignore the shitass drawing)

sinful sand
#

hm

lethal wraith
#

(notice how there's a triangle)

sinful sand
#

i see it