Hi

A few question i am stuck on and need help:

1)$\displaystyle \frac{4sin^2(x)-4sin^4(x)}{sin(2x)}$

this is what i have done but it is incorrect.

$\displaystyle =\frac{4sin^2(x)(1-sin^2(x))}{sin(2x)}$

$\displaystyle =\frac{4sin^2(x)(cos^2(x))}{2sin(x)cos(x)}$

$\displaystyle =2sin(x)cos(x)$

2)$\displaystyle \frac{1}{2}sin(x)cos(x)$

3)$\displaystyle \frac{tan(x)}{1-tan^2(x)}$

P.S