Let (x) = tan 2 x and g(x) = sec 2 x. (a) Use an identity and

Let ƒ(x) = tan² x and g(x) = sec²x.
(a) Use an identity and prove ƒ'(x) = g'(x) without directly computing ƒ'(x) and g'(x).
(b) Now verify the result in (a) by directly computing ƒ'(x) and g'(x).