Switch all x variables to -x.
If the new equation is the same as before (y = x^2 + |x|) then the equation is even.
If the new equation is the exact opposite (y = x^3 --> y = -x^3) then the equation is odd.
If the equation turns out to be neither (y = x+1) then the answer is neither.
It can never be both.
Try graphing it out too! Even ones are symmetrical across the y axis. Odd ones can be rotated 180 degrees and still create the same line.
