I am still having terrible trouble with my class. Any help is greatly appreciated and I want to thank everyone who has helped me out in the past.

The first problem I am having trouble with is finding f prime of the function

((2x^2)(tan(x))/(sec(x))

Now my first inclination is ((sec(x))((4x)(sec^2(x)))-((2x^2(tan(x)))((sec(x))(tan(x)))))/(sec(x)(tan(x)))

But I input this and it comes out incorrect. Any ideas? Is it a typo or am I doing it wrong?