Let U = 2 − ex.
Don't forget to rewrite the bounds in terms of u.
The derivative of an INDEFINITE integral, is the original function (FTC, pt.1) But the derivative of a DEFINITE integral is the original function times the derivative of the bounds.
Let u = sec(x).
arctan(u) + C =
Now rewrite the answer in terms of x.
Recall that x4 = (x2)2.
And don't forget about the bounds!