Tentukan turunan pertama fungsi trigonometri f(x) = 3 cos (2 - 4x -3x^2)

f(x) = 3 cos (2-4x-3x²)
f'(x) = -3(-4-6x)sin(2-4x-3x²)
=(12+18x)sin(2-4x-3x²)

Turunan
f(x)= 3 cos(2 - 4x - 3x²)

u = 2 - 4x - 3x²
du/dx = -4 - 6x

y = 3 cos u
dy/du = -3 sin u

f' (x)= dy/dx
dy/dx = dy/du.. du/dx
f '(x) = - 3 sin u. (-4-6x)
f '(x)= -3(-4 -6x) sin (2 - 4x - 3x²)
f'(x) = (12 +18x) . sin(2 - 4x - 3x²)
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