Hello Everyone! Today we are asked to prove that both this expressions are true: and . To be quite honest, I am not very sure as to how I can prove these, but my attempt for the first one, I was able to prove that but was unsure as to how I would be able to turn it into which is what I need to prove the first equality.

As for the second one I did something like this:

So that:

and by properties of odd and even function:

Thus, it should be true to say that :

The proof above, for me, is quite sloppy, but I think I could live with that. But for the first one, I really have no idea as to how to prove it. Anyone got some ideas as to how I should prove both equivalence? Thanks everyone in advance!