- #1
flyingpig
- 2,579
- 1
Homework Statement
[tex]\int e^x \frac{1 + sin(x)}{1 + cos(x)}\;dx[/tex]
The Attempt at a Solution
Apparently there is a trick involving e^x integrals like this
[tex]\int e^x[f(x) + f'(x)] dx = e^x f(x) + C[/tex]
Now my question is not how to compute the integral above but where did this [tex]\int e^x[f(x) + f'(x)] dx = e^x f(x) + C[/tex] identity came from?? How does one know this exists?