Answer:
1 + cosx - 1 - cosx
1-cosx 1+cosx
Multiplying by conjugate
1 + cosx * 1+cosx - 1 - cosx * 1-cosx
1-cosx 1+cosx 1+cosx 1 -cosx
(1+cosx)² - (1-cosx)²
1- cos²x 1- cos²x
1 + 2cosx + cos²x -(1 - 2cosx + cos²x)
1-cos²x
4cosx = 4 cosx . 1 4 cotx cosecx
sin²x sinx sinx
Explanation: