5 cos^ 3α tg 3α Помогите пожалуйста)

5cos³(3α)·tg(3α)=5cos³(3α)·(sin(3α)/cos(3α))=5cos²(3α)·(sin(3α)= =5cos(3α)·(sin(3α)·cos(3α))=5cos(3α)·sin(6α)/2=(5sin6αcos3α)/2