Question

Suppose
f(π/3) = 5 and f '(π/3) = −7,
and let
g(x) = f(x) sin x
and
h(x) = (cos x)/f(x).
Find the following.
h'(π/3)

Answer 1

is it not quotient rule for derivative?

Answer 2

ive tried but i didnt get it

Answer 3

what do you get so far?

Answer 4

i know the rule is (u/v)' = (u'v - uv')/v^2 and..
h' = (cos(x)'f(x) - cos(x)f'(x))/f(x)^2

Answer 5

(cos x)'= ?