Average and instantaneous gradient
Average and instantaneous gradient

A straight line has one constant gradient, but a curve changes steepness from point to point. The gradient between two points on a curve is the average gradient, found from the secant or chord joining them.
Step-by-step lessons on Edexcel AS Level Maths 12.2 Differentiation from first principles. Each one builds up to exam-style questions. Build fluency in the core algebra, surds and trigonometry topics early, since they underpin the calculus, statistics and mechanics content that follows.