What is int cosx-sin(x/2-pi) cosxsin(x2π)?

1 Answer
Nov 27, 2016

int (cos(x) - sin(x/2- pi))dx = sin(x) - 1/2cos(x/2) + C(cos(x)sin(x2π))dx=sin(x)12cos(x2)+C

Explanation:

Given: int (cos(x) - sin(x/2- pi))dx(cos(x)sin(x2π))dx

Use the identity, sin(A - B) = sin(A)cos(B) - cos(A)sin(B)sin(AB)=sin(A)cos(B)cos(A)sin(B):

sin(x/2 - pi) = sin(x/2)cos(pi) - cos(x/2)sin(pi) sin(x2π)=sin(x2)cos(π)cos(x2)sin(π)

sin(x/2 - pi) = -sin(x/2) sin(x2π)=sin(x2)

Substitute into the integrand:

int (cos(x) - (-sin(x/2)))dx(cos(x)(sin(x2)))dx

int (cos(x) + sin(x/2))dx = sin(x) - 1/2cos(x/2) + C(cos(x)+sin(x2))dx=sin(x)12cos(x2)+C