Question

Write 4 sin(3x) cos (2x) as a sum or difference

Answer 1

2sin(x) + 2sin(5x)

Explanation:

4sin(x)cos(2x)

=4sin(2x+x)cos(x+x) = 4[sin(2x)cos(x)+cos(2x)sin(x)]

= 4sin(2x)cos(x) + 4sin(x)cos(2x)

= 4sin(x+x)cos(x) + 4sin(x)cos(x+x)

= 2sin(x) + 2sin(5x)