find the coordinates of the turning points of the curve y = 2x^4-4x^3+3, and determine the nature of these points

To begin, we must first use the fact that turning points of a graph occur at points where the gradient is equal to zero, in other words, points where dy/dx =0. Differentiating the equation with and setting to zero gives dy/dx = 8x3-12x2=0, then, solving for x we get x = 0 and x = 3/2. Putting these x values back into the original equation will give us the coordinates of the turning points which are (0,3) and(3/2,-3/8).The second part of the question asks us to determine the nature of the turning points, for which we will have to use the second derivative. Differentiating dy/dx again gives d2y/dx2=24x2-24x. at x= 3/2, d2y/dx2= 18 which makes it a minimum point since d2y/dx2>0. x=0, d2y/dx2=0 which means it could either be a minimum, maximum, or point of inflection, we will have to run further tests to determine the nature of this point.

JN

Related Maths A Level answers

All answers ▸

What is the difference between mutually exclusive and indepedent events?


How do you sketch the graph of a function?


Find the exact solution to the equation: ln(3x-7) =5


Three forces of magnitude 50N, PN, QN all act in a horizontal plane in equilibrium. The diagram shows the forces. DIAGRAM: QN = EAST, 50 = SOUTH, PN = 120 DEGREES ANTICLOCKWISE FROM QN a) Find P. b) Find Q.