Consider the point P=(1,2) on the graph of y = x + m = Let Q = (1 + h, 1+h+1+h) be another point on the same curve. What is the slope of the line passing through P and Q? What is the significance of this slope? m is the slope of the tangent line to y. m = m is the slope of the normal line to y. 1 m = x . h² +2 h(h+1) ' m = h (h+1) m is the slope of the tangent line to y at point P when h approaches 0. h² +2 h(h+1) h (h+1) m is the slope of the tangent line to y at point P when h approaches 1. Om is the slope of the secant line passing through P and Q, and has nothing to do with the tangent line.