The vertical profile of a section of a roller coaster track is modelled by the curve with equation y=2x3−24xy = 2x^3 - 24xy=2x3−24x, where yyy is the vertical displacement in decametres and xxx is the horizontal distance in decametres from a support pylon.
Point AAA on the track is located at horizontal distance x=2x = 2x=2.
Point BBB on the track is located at horizontal distance x=2+hx = 2 + hx=2+h.
Show that the gradient of the chord ABABAB is given by 2h2+12h2h^2 + 12h2h2+12h.
Explain how the result of part (a) can be used to show that AAA is a stationary point on the track section.
717 exam-style questions on Edexcel A Level Maths Differentiation, covering 9.1 Differentiating sin x and cos x, 9.2 Differentiating exponentials and logarithms, 9.3 The Chain Rule, 9.4 The Product Rule, 9.5 The Quotient Rule, 9.6 Differentiating Trigonometric Functions, 9.7 Parametric Differentiation, 9.8 Implicit Differentiation, 9.9 Using Second Derivatives, and 9.10 Rates of Change. Each one has a worked solution and a mark scheme showing where the marks go.