Find both stationary points for y= 4x^(3)-3x^(2)-60x+24. Also find the nature of those points.

y= 4x3- 3x2- 60x+ 24dy/dx = 12x2- 6x- 60 = 2x2- x- 10 = (2x-5)(x+2)
So stationary points are at x= 5/2 and x= -2
d2x/dy2 = 24x - 6
24(5/2) - 6 = positive so this is a minimum point
24(-2) - 6 = negative so this is a maximum point

WM

Related Maths A Level answers

All answers ▸

Find the max/min value of the function: f(x) = 5x^2 - 20x + 15


(a) Express (1+4*sqrt(7))/(5+2*sqrt(7)) in the form a+b*sqrt(7), where a and b are integers. (b) Then solve the equation x*(9*sqrt(5)-2*sqrt(45))=sqrt(80).


Given that y > 0, find ∫((3y - 4)/y(3y + 2)) dy (taken from the Edexcel C4 2016 paper)


Find the general solution, in degrees, of the equation 2 sin(3x+45°)= 1