Calculus
posted by Cynthia .
Evaluate (Integral) sin 4x cos^2 4x dx.
A. Cos^3(4x)/3 + C
B. Cos^3(4x)/3 + C
C. Cos^3(4x)/12 + C
D. Cos^3(4x)/12 + C

Calculus 
MathMate
Use the substitution
p=cos(4x)
dp=4sin(4x)dx
I=∫sin(4x)cos²(4x)dx
=∫(1/4)p²dp
Can you take it from here?
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