The point P P\,P lies on the curve with equation y=ln(13x)\displaystyle y = \ln(\frac{1}{3}x)y=ln(31x). The xxx-coordinate of P P\,P is 3. Find an equation of the normal to the curve at the point P P\,P in the form y=ax+by = ax + by=ax+b, where a a\,a and b b\,b are constants.
Practise Edexcel A Level Old Maths Differentiation with exam-style questions for A Level Old Maths. 14 questions, matched to the Edexcel A Level Old Maths (9371) specification and written in Unit exams C1, C2, C3 and C4 plus two applied units (e.g. S1 and M1) style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.