Question 1140243
If p = cos x + cos 2x and q = sin x + sin 2x, find the value of 2pq.
-------
2pq = 2*(cos(x) + cos(2x))*(sin(x) + sin(2x))
= 2*(sin(x)cos(x) + sin(x)*sin(2x) + cos(2x)*sin(x) + cos(2x)*sin(2x))