The point P P\,P lies on the curve with equation y=sec3xy = \sec 3xy=sec3x with x x\,x coordinate π9\displaystyle \frac{\pi}{9}9π.
Find an equation of the normal to the curve at the point PPP.
74 exam-style questions on OCR A Level Maths 1.7.18 Chain rule (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.