Hello mathlovers!

I have a sticky problem where I am unable to see how to simplify Sin(2u) where u=tan^-1 x

I get Sin(2tan^-1 x). How do you rewrite in a simpler math-language as wolfram does?

Not sure I follow how they compute this operation. Could someone fill me in?

Love

Anhard

Well Done and short Solution for the problem.

Your picture is blurred, so I cannot see what you are trying to accomplish. I hope the following helps:

u=tan-1 x implies tan(u)=x

By Pythagorean theorem:

sin(u)=x/sqrt(x^2+1)

cos(u)=1/sqrt(x^2+1)

sin(2u) = 2sin(u)*cos(u)

sin(2u) = 2x/(x^2+1)