What is the integral of sin2(x)cos4(x)dx?

1 Answer
Jun 5, 2016

116(x14sin(4x))+16sin3(x)cos3(x)+C

Explanation:

sin2(x)cos4(x)dx

Applying integral reduction,

sin2(x)cosn(x)dx = (sin3(x)cosn1(x)2+n) +(n12+n) sin2(x)cosn2(x)dx

so,
sin2(x)cos4(x)dx
=sin3(x)cos3(x)6+36cos2(x)sin2(x)dx

=sin3(x)cos3(x)6+36cos2(x)sin2(x)dx

We know,
cos2(x)sin2(x)dx=18(x14sin(4x))

Then,
=sin3(x)cos3(x)6+3618(x14sin(4x))

Simplifying,
=116(x14sin(4x))+16sin3(x)cos3(x)

Adding constant to the solution,
=116(x14sin(4x))+16sin3(x)cos3(x)+C