How do you find the integral of (sinx)^3 dx(sinx)3dx?

1 Answer

Refer to explanation

Explanation:

We know that

sin 3x = 3sinx - 4 (sin x)^3=>4(sinx)^3=3sinx-sin3x=> (sinx)^3=3/4*sinx-1/4sin3x sin3x=3sinx4(sinx)34(sinx)3=3sinxsin3x(sinx)3=34sinx14sin3x

Hence we have that

int (sinx)^3 dx=int (3/4*sinx-1/4*sin(3x))dx=-3/4cosx+1/12cos3x+c(sinx)3dx=(34sinx14sin(3x))dx=34cosx+112cos3x+c