Ask your own question, for FREE!
Mathematics 11 Online
OpenStudy (dls):

Calculus help again!

OpenStudy (nincompoop):

and here we are

OpenStudy (nincompoop):

calc 3?

OpenStudy (nincompoop):

@iambatman

OpenStudy (dls):

\[\LARGE y= \tan^{-1} (\frac{1+x}{1-x}_\] Prove that : \[\Large y_n=(-1)^{n-1}(n-1)! \sin ^n \theta \sin n \theta \] where theta=cot^-1 x

OpenStudy (dls):

\[\LARGE y= \tan^{-1} (\frac{1+x}{1-x})\]

OpenStudy (nincompoop):

inverse?

OpenStudy (nincompoop):

so we are talking about arctan

OpenStudy (dls):

My attempt.. \[\LARGE y = \frac{\pi}{2} - \cot^{-1}\cot(\frac{\pi}{4}-x)\] \[\LARGE y = (\frac{\pi}{4}-\cot \theta)\] \[\Large y_1 = - cosec^2 \theta\] \[\Large y_2 = -2cosec \theta cosec \theta \cot \theta\] can't find the pattern

OpenStudy (nincompoop):

laughing out loud

OpenStudy (dls):

:|

OpenStudy (nincompoop):

you have two cosec that's a pattern to watch out for laughing out loud

OpenStudy (dls):

but the required pattern is \[\Large y_n=(-1)^{n-1}(n-1)! \sin ^n \theta \sin n \theta\]

OpenStudy (nincompoop):

whip out your book

OpenStudy (dls):

If I put n=2 I get \[\Large y_2=(-1) \sin ^2 \theta \sin 2\theta\]

OpenStudy (dls):

thats kind of contradicting :s

OpenStudy (nincompoop):

when proving, don't you have to start with definition?

OpenStudy (rational):

another approach |dw:1408780937713:dw|

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!