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HSC 2013 Maths Marathon (archive) (1 Viewer)

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Menomaths

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Re: HSC 2013 2U Marathon

Code:
\sqrt{x}
 

mahmoudali

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Re: HSC 2013 2U Marathon

You need to provide more working out when integrating tanx with respect to x

also
i skipped so many steps because i cbfed showing it using this latex bs wastes to much time
and mathewYan can you please tell me where i made mistakes?
 

HeroicPandas

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Re: HSC 2013 2U Marathon

i skipped so many steps because i cbfed showing it using this latex bs wastes to much time
and mathewYan can you please tell me where i made mistakes?
at least in the end of your working, have a quick outline how you integrated tanx with respect to x (unless you memorised it)

AND, have you ever learnt how to integrate something that has an absolute?

(gotta choose plus or minus carefully)
 

integral95

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Re: HSC 2013 2U Marathon

Hm, was this your expression:



??

That is what I got initially
Lol whoops forgot about the 1/2 at the front of the bracket, (sigh I forgot about trapezoidal rule )
 

Sy123

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Re: HSC 2013 2U Marathon

Fixed latex, that is the right idea anyway, if you didn't make any mistakes its right

EDIT: Second integral is wrong
EDIT2: First integral is wrong as well
 
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mahmoudali

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Re: HSC 2013 2U Marathon

why does my writing part leave no spaces :(
 

superSAIyan2

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Re: HSC 2013 2U Marathon

Although your final answer is correct, your working out suggests that the answer is -ln(root2).

When you square root the cot^2 x it becomes abs (cotx). Now the integral is defined over the interval x = -pi/4 to x = 0. In this region cotx is negative, so abs(Cotx) = -cotx. Therefore you must put a minus sign in front of the integral.
 
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