Find slope of a curve without calculus Is it possible to find the slope of a curve at a point without using calculus?

Slope of a curve at a specific point MUST be a limit, which I am not sure whether you classify as calculus or not. Slope is by definition a function of two distinct points, and the only interpretation of "slope of a curve at a point" is that of two points approaching each other along the curve.
If you are not allowed to use limits, then no because both points have the same x and y coordinates, causing a 0/0 evaluation which is meaningless.
