Just plug the "y's" in like they were numbers and your answer will be a function. Here's an example:
I am working on this question for calculus, but I am a bit confused by the y's in the range of the integral.
Here is the question, which asks you to find p'(y).
I am a bit confused as to what to do next, would subbing 9y for x be all I need to do for this question? (Fundamental theorem of calculus part 1)
Thanks a lot.