1 trigonometry Q.

Find x，give you answer in the interval from －180degree to 180degree.
3Sinx=4Sin^3 x
Sol
3Sinx=4Sin^3 x
4Sin^3 x－3Sinx=0
Sinx(4Sin^2 x－3)=0
Sinx=0 or Sin^2 x=3/4
Sinx=0 or Sinx=√3/2 or Sinx=－√3/2
x=－180度 or x=0度 or x=180度or x=60度 or x=120度
orx=－60度or x=－120度