So you can't use the definition of cosh(x)?
You're making this too hard. "Fractions" is not a good way to think of this. For instance integrating is integrating a fraction but is very complex. In your problem you have variables over a constant. Notice that . And you should know that any constant in front of an integral can be brought outside of the integral and applied to the answer after integration. So for this one, your constant is 1/2, bring it out and apply it after.