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 ▸

The point P lies on a curve with equation: x=(4y-sin2y)^2. (i) Given P has coordinates (x, pi/2) find x. (ii) The tangent to the curve at P cuts the y-axis at the point A. Use calculus to find the coordinates of the point A.


Find exact solution to 2ln(2x+1) - 10 =0


y = (x^3)/3 - 4x^2 + 12x find the stationary points of the curve and determine their nature.


Find the minimum value of the function, f(x)= x^2 + 5x + 2, where x belongs to the set of Real numbers