HSC 2014 MX2 Marathon (archive) (3 Viewers)

[hit patel]

Re: HSC 2014 4U Marathon

do i know u?

Well I do know u. you are the next 4U state ranker

 

[hit patel]

Re: HSC 2014 4U Marathon

Very good but there is one detail in part ii you missed, The graph (on the right branch) actually intercepts the asymtote at (1,1) and approaches y=x from the top side. Other than that well done.

hey can we get some volume questions or like some non integral mechanics or like some integration?

 

[dunjaaa]

Re: HSC 2014 4U Marathon

oh yes, you got me there haha reminds me of a past hsc curve sketching question

 

[dunjaaa]

Re: HSC 2014 4U Marathon

na not even close man, there's about 1000 other people in this state that are better than me

 

[hit patel]

Re: HSC 2014 4U Marathon

na not even close man, there's about 1000 other people in this state that are better than me

HSC is not all about smartness. Its more of how the situations favour you. See me. I used a lot of proofs for one of my 4U tasks that the teacher didnt approve and yeh dropped down to 84% straight. I am not saying i am smart. To say the truth, I am actually stupid but still my proofs made it look so much quicker and more efficient. Really dont know why.It all depends on situations, and from what I see, u can choose ur situation

 

[Davo_01]

Re: HSC 2014 4U Marathon

 

[hit patel]

Re: HSC 2014 4U Marathon

(b>a)

arcsin (secb) - arcsin (seca)

 

[Davo_01]

Re: HSC 2014 4U Marathon

arcsin (secb) - arcsin (seca)

Are you sure?

 

[hit patel]

Re: HSC 2014 4U Marathon

Are you sure?

Wait is it wrong?

 

[hit patel]

Re: HSC 2014 4U Marathon

arccos(sec(b))-arccos(sec(a))?

Probably right... But I dont know why sin isnt right>? if it was cot then it would allow cos but...

 

[Davo_01]

Re: HSC 2014 4U Marathon

Wait is it wrong?

Well its kinda right but there is something wrong about it, can you figure it out?

 

[dunjaaa]

Re: HSC 2014 4U Marathon

consider the sec function and the condition given

 

[hit patel]

Re: HSC 2014 4U Marathon

arcsin (secb) - arcsin (seca)

oh

 

[Davo_01]

Re: HSC 2014 4U Marathon

anyways i will simplify;
arcsin (b.sqrt(1-a^2) - a .sqrt (1-b^2)) ?

Its nothing to do with that, what is the domain of Inverse Sin and the range of secx?

 

[dunjaaa]

Re: HSC 2014 4U Marathon

idk i thought there had to be some condition with the sec function

 

[hit patel]

Re: HSC 2014 4U Marathon

consider the sec function and the condition given

Wait b>a anyways. Isnt that what you always consider?

 

[Davo_01]

Re: HSC 2014 4U Marathon

Wait b>a anyways. Isnt that what you always consider?

No its the fact that the range of secx is outside the domain of inverse sin, so therefore the integral is actually undefined!

 

[Davo_01]

Re: HSC 2014 4U Marathon

No its the fact that the range of secx is outside the domain of inverse sin, so therefore the integral is actually undefined!

The only case where it could be defined is if a=b=0 which i eliminated with the given condition

 

[hit patel]

Re: HSC 2014 4U Marathon

No its the fact that the range of secx is outside the domain of inverse sin, so therefore the integral is actually undefined!

Ah. Nice question. I tried to draw the arcsin curve of sec x but couldnt but still didnt realise that.

 

[dunjaaa]

Re: HSC 2014 4U Marathon

-1<=sec(a)<sec(b)<=1?
which is undefined except a=b=0