Turunan fungsi dari F(x) = (2x^2 + 3) cos 2x

misal:
U = 2x^2 + 3 ---> U' = 4x
V = cos 2x ---> V' = -2 sin 2x

f(x) = U . V
f'(x) = U'V + UV'
= 4x cos 2x + (2x^2 + 3) (-2 sin 2x)
= 4x cos 2x - 4x^2 sin 2x - 6 sin 2x