Even Function: A function such that $f(-x) = f(x)$ for all $x$ in its domain; symmetric with respect to the y-axis.
Symmetry:A property where one half of something mirrors the other half; in functions, common types include symmetry about the y-axis or origin.
Net Change Theorem:A theorem stating that the integral of a rate of change (derivative) over an interval gives the net change in the quantity over that interval.