I am doing a derivative of y=(tan^-1 x )^2
Help will be appreciated:)

Question

I am doing a derivative of y=(tan^-1  x )^2
Help will be appreciated:)

anonymous · Answer

Okay, 
so I have already done
$$y=(\tan^{-1}x)^2$$$$\tan(~\sqrt{y}~)~=~x$$

and Just like by other questions, we have been drawing the angle of the function.

Here we would do,
|dw:1412696845220:dw|

anonymous · Answer

And how do I use this picture/diagram/triangle
for the derivative?

hartnn · Answer

no sure why you need the triangle
but you can differentiate 

y= (tan^-1 x)^2 
using chain rule

provided you know/can use the derivative of tan^-1 x

anonymous · Answer

I was offline.

I can't use the derivative of tan^-1 x.

This is an exercise from a section of the proofs of the deriv. of the inverse trig. functions.

anonymous · Answer

My teacher did it using the triangle, so I want to know how would it be done in a different way then using
sec^2x=tan^2x+1
after deriving tan(y).