Functions- How can I tell if a function is odd or even?

Answer 1

Function is even if f(x) = f (- x)
Example 1
f(x) = x²
f(-x) = (-x)² = x²
f(x) = x² is an even function.

Example 2
f(x) = x³
f(-x) = (-x)³ = - x³
f(x) = x³ is an odd function.

Answer 2

A function is even if and only if f(x) = f(-x).
A function is odd if and only if f(-x) = -f(x).