Is this correct, feel like I am missing a step.

Differentiate 4 = J 4 x 3 + (ex 2 - 1 dy - dx ( 2 1 4 x 3 + 6 x 2 1 d x 3 14 2 x * + 6 9x x + ( ) 2 4 x 3 thex 2 - 1 12 x 2 + 12 x 1 = 12 x 2+ 12 x 2 5 4 x 3 + 6 2 x 2 - 1 = 12 ( x 2 4 x ) 2 / 4 x 3 Hox 2- 1 y! = 6 ( x 2 + x ) J 4 x 3 + 6 x 2 - 1