Thanks to all of you who support me on Patreon. You da real mvps! $1 per month helps!! 🙂 https://www.patreon.com/patrickjmt !! Secant Line: Finding an Equation for a Secant Line. Here we look at finding the equation of a secant line for a given curve at two given points. The slope of the secant line is the average rate of change of the function over that interval.