Question

expand sin3(theta) in terms of cos and sin

Answer 1

sin3x=3sinx-4(sinx)^3

Answer 2

take sinx common
=sinx(3-4(sinx)^2)
=sinx(3-3(sinx)^2-(sinx)^2)
=sinx(3(1-(sinx)^2)-(sinx)^2)
=sinx(3*(cosx)^2-(sinx)^2)
solve further now