d/dx cos^2(5x^3)
= d/dx [cos(5x^3)]^2
= 2[cos(5x^3)]
= - 2[cos(5x^3)] * sin(5x^3)
= - 2[cos(5x^3)] * sin(5x^3) * 15x^2
= - 30[cos(5x^3)] * sin(5x^3) * x^2
Explanation:
d/dx x^n = nx^(n - 1)
d/dx cos x = - sin x
Chain rule:
d/dx f(g(...w(x))) = f’(g(...w(x))) * g’(...w(x)) * ... * w’(x)
Step-by-step explanation:
f(x) = cos²(5x³)
f(x) = (cos(5x³))²
Use chain rule to find the derivative:
f'(x) = 2 cos(5x³) × -sin(5x³) × 15x²
f'(x) = -30x² sin(5x³) cos(5x³)
If desired, use double angle formula to simplify:
f'(x) = -15x² sin(10x³)
