A curve has equation y = 20x -x^(2) - 2x^(3). The curve has a stationary point at the point M where x = −2. Find the x coordinates of the other stationary point.

First you must differentiate the given equation. This give you 20-2x-6x2. Since we are told that one of the stationary points is at x=-2, this is one of the factors of the differential equation. Meaning that the differential equation fully factorised is (10-6x)(2+x) =0.Wherever the differential equation has a solution pertaining to 0, this is a stationary point of the original curve. Hence x = 5/3 is the x coordinate of the second stationary point.

LW

Related Maths A Level answers

All answers ▸

Find the coordinates of the stationary point of the graph y = 3x^2 - 12x


Given the equation 0=5x^2+3xy-y^3 find the value of dy/dx at the point (-2,2)


A uniform ladder is leaning against a smooth wall on a rough ground. The ladder has a mass of 10 kilograms and is 4 metres long. If the ladder is in equilibrium, state an equation for the coefficient of friction of the ground


Use Simpson's rule with 5 ordinates (4 strips) to find an approximation to "integral between 1 and 3 of" 1/sqrt(1+x^3) dx giving your answer to three significant figures.