Question

If 2 sin theta minus 1=1.prove that sin30 = 3 sin theta minus 4sin^3 theta

Answer 1

Answer:

2 sinθ - 1 = 1

sinθ = 1

sin30 = 3 sinθ - 4sin³θ

1/2 = 3 - 2/2

1/2 = 1/2

hence proved