Posted by Dan on .
find the following derivatives:
f(x) = (2x+5)/(x^23)
f'(x)= (2)*(x^2 3)(2x+5)*2x/(x^23)^2
is that correct???
f(x)= (lnx)(cos x)
f'(x)= 1/x*sinx
or do i have to use the product rule??
thank you.

calculus 
Anonymous,
the first one is correct, with the second you have to use the product rule