pembuktian f(x) =secan x turunannya f'(x) = secan x .tan x

jawab

f(x)= sec x 
f(x)= 1/cos x

u = 1
u' = 0

v = cos x
v' = - sinx

f(x) = u/v
f '(x )= (u'v - uv')/v²

f'(x) = (0- 1(-sin x) /(cos² x)
f'(x) = sin x / cos² x

f' (x)=  sin x/cos x . 1/cos x
f' (x ) = tan x . sec x
atau

f'(x) = sec x. tan x