First, bring f(-x) into the analytical formula and simplify the deformation to see if it is equal to f(x) or f(x).
If f(x)=f(-x), it is an even function; On the other hand, if f (x) = f (-x), it is odd function.
Monotonicity: according to the definition: (1). Let x 1, x2 belong to the domain, x1; 0, the function monotonically decreases in the domain, and conversely increases.
I don't think you can understand it. You'd better find a topic and I'll send you the steps.