y= tan^3 (sqrt(4 - x^4))

i did

y = [tan(sqrt4 - x^4)]^3

y'= 3[tan(sqrt4 - x^4)]^2 * [sec^2 (sqrt(sqrt4 - x^4))]*[(4-x^4)^-1/2]'

= 3[tan(sqrt4 - x^4)]^2 * [sec^2 (sqrt(sqrt4 - x^4))]*[1/2(4-x^4)^-1/2](4x^3)

= 12x^3[tan(sqrt4 - x^4)]^2 * [sec^2 (sqrt(sqrt4 - x^4))]*[1/2(4-x^4)^-1/2]

is this the final answer?

do i have to do something with [1/2(4-x^4)^-1/2] ?