Integral 2 cos (1/3pi - 4x)

dianggap gini 2 cos((1/3)pi - 4x) dx
u = (1/3)pi - 4x --> du = -4 dx
dx = -(1/4) du
= 2 int cos u (-1/4) du
= -(1/2) int cosu du
= -(1/2) sinu + c
= -(1/2) sin(pi/3 - 4x) + c