To fins the equation of a tangent to a curve at a point we have to find the gradientat that point. Ifandare functions ofwe findand substitute a value forinto this expression. If we have to find the equation of the normal to a curve at a pointwe findIf we have the coordinatesor only one of these, we may have to find the value ofby solving one or both of the equations

Example:Find the equation of the tangent and normal when

When

Equation of tangent:

Equation of normal: