This model can be used to predict the fuel consumption of a car, y y\,y miles per gallon, for a car travelling at x x\,x miles per hour.
y=60−0.02(x−50)2 y = 60 - 0.02(x - 50)^2 y=60−0.02(x−50)2Calculate the fuel consumption, in miles per gallon, of a car travelling at 70 miles per hour.
Deduce the speed at which the car has the greatest fuel efficiency.
State, giving reasons, the limitation on the values of xxx
Hence find the range of speeds for which the fuel consumption is at least 52 miles per gallon.
211 exam-style questions on Edexcel A Level Maths Quadratics, covering 2.1 Solving Quadratics, 2.2 Completing the Square, 2.3 Sketching Quadratic Graphs, 2.4 The Discriminant, and 2.5 Modelling with Quadratics. Each one has a worked solution and a mark scheme showing where the marks go.