Define `y=cos^(-1)(4x^(3)-3x)` in terms of `cos^(-1)x`

Explanation

Let `cos^(-1)x=theta(x=costheta)impliestheta epsilon[0,pi]implies3theta=[0,3pi]`
Now `y=cos^(-1)(4x^(3)-3x)=cos^(-1)cos3theta`
`={(3theta,3theta epsilon[0,pi],"or",theta epsilon[0,(pi)/3]),(2pi-3theta,3theta epsilon[pi,2pi],"or",theta epsilon[(pi)/3,(2pi)/3]),(3theta-pi,3theta epsilon[2pi,3pi],"or",theta epsilon[(2pi)/3,pi]):}`
`y=cos^(-1)(4x^(3)-3x)={(3cos^(-1)x, ,, 1/2lexle1),(2pi-3cos^(-1)x,,,-1/2lexlt1/2),(-2pi+3cos^(-1)x,,,-1lexlt-1/2):}`