This algebra 2 and precalculus video tutorial explains how to determine whether a function f is even, odd, or neither algebraically and using graphs. This video contains plenty of examples and practice problems using variables and constants. First, plug in -x into the equation and see if the sign changes. If all signs change, it’s an odd function. If they all remain the same, then it’s an even function. If some change while others do not, the function is neither even or odd. For graphs, even functions are symmetric about the y axis. For odd functions, the symmetry exists about the origin. For circles with even and odd properties, it does not pass the vertical line test and is therefore not a function.