Hey, I have a problem that is listed below and I know I might be rushing it a bit, simply because it hasn't been really taught yet (or to my knowledge), but the problem is below:

I know that for C) x has to be equal to zero. For A), I have no idea how to isolate for x, and for B) I think sin(x) - 1 = x. However, I do not know if this is a valid claim because of two x variables in B.

First question is how do I prove such claims? Second question is how do I even isolate for X in the first part.

Thank you.