I was under the impression that you needed Calculus to find the instantaneous velocity at a point when dealing with non-linear functions. I'm near positive that statement is false or at least only partially correct. f(x)=√x is a non-linear function, but the "line" (or curve?) is accelerating uniformly, so you can figure this out without the use of any Calculus. Pick a point, B. Pick another point to the left of point B and call it point A. Pick yet another point on the curve, but this time move to the RIGHT of point B and call it point C. You might have to modify the location of one of your points, but just make sure point A and point C are equidistant to your midpoint B. Find the slope of AB. Now find the slope of BC (you probably see where this is going) If you take the mean of the two, you should have figured out Vinstant at point B. This method should work for any non-linear function with a "line" that is accelerating uniformly, and you don't need any Calculus. So how should I edit my statement from my intro? You need Calculus to find the instantaneous velocity when dealing with a non-linear function that isn't accelerating uniformly?