pi -- 61 / | | sin(8*x)*cos(2*x) | ----------------- dx | 4 | / 0
Integral((sin(8*x)*cos(2*x))/4, (x, 0, pi/61))
/2*pi\ /8*pi\ /2*pi\ /8*pi\
cos|----|*cos|----| sin|----|*sin|----|
1 \ 61 / \ 61 / \ 61 / \ 61 /
-- - ------------------- - -------------------
30 30 120
=
/2*pi\ /8*pi\ /2*pi\ /8*pi\
cos|----|*cos|----| sin|----|*sin|----|
1 \ 61 / \ 61 / \ 61 / \ 61 /
-- - ------------------- - -------------------
30 30 120
1/30 - cos(2*pi/61)*cos(8*pi/61)/30 - sin(2*pi/61)*sin(8*pi/61)/120
Use the examples entering the upper and lower limits of integration.