hmmm i think im doing it correctly but im not quite sure and i dont know how to simplify trig terms...help please...

$\displaystyle (5 - cos x) / (5 + sin x)$

I got this far by using the quotient rule...am i correct so far???

---> $\displaystyle (sin x( 5 + sinx) - (5-cos x)cos x ) / 5 + sin^2x $

Also another question......

Find f'

f(x) = $\displaystyle sin^2 x + cos^2 x$

i got .... $\displaystyle 2 sin x . cos x + 2 cos x . -sin x$

correct??

how would i simplify it?