Title: 12_1 Tangents and Normals
Course: HELM Workbooks 2023-2024 > Section: HELM 12: Applications of Differentiation

Introduction

In this Section we see how the equations of the tangent line and the normal line at a particular point on the curve \(y=f(x)\) can be obtained. The equations of tangent and normal lines are often written as

\(\qquad y=mx+c,\ \ \ \ \ \ y=nx+d\)

respectively. We shall show that the product of their gradients \(m\) and \(n\) is such that \(mn\) is \(-1\) which is the condition for perpendicularity.