Could someone be so kind as to derive these functions for me? My answers are not what the back of the book has but i dont now where I go wrong so if you could show all your work I would appreciate it.

$\displaystyle y = cos^3x$

$\displaystyle y = sin(x^3)$

$\displaystyle f(x) = cos(5x-3)$

$\displaystyle f(x) = sin^2xcos (\frac{x}{2})$

$\displaystyle f(x) = cos^2(4x^2)$

$\displaystyle g(x) = \frac{cosx}{cosx-sinx}$

Thanks

Chris