I just wanted to make sure that I'm taking the derivative of this correctly, my problem is:

y=sec^2(x^4)

MY Answer: y'= 2sec(x^4)(sec^2 (x^4)) (tan^2 (x^4))(4x^3)

So is it right, if not please try to explain to me what I'm doing wrong because I've done this problem like 10 times and I get the same answer.

Thanks.