Find the co ordinates and nature of the turning points of the curve C withe equation, y=2x^3-5x^2-4x+2

Firstly, Differentiate the equation to find dy/dx. (dy/dx = 6x^2-10x-4)dy/dx shows the rate of change of the curve at a point, so at the stationary point dy/dx =0. So, put dy/dx = 0 and solve using factorisation. 6x^2 -10x -4=0,(x-2)(6x+2)=0x=2 or x=-1/3To find the y co ordinate plug these x values into the equation of the curve. y=2x2^3-5x2^2-4x2+2=-10y=2x(-1/3)^3-5x(-1/3)^2-4x(-1/3)+2=2.70The nature of the turning point is found using the double derrivative. So differentiate dy/dx to find d^2y/dx^2.d^2y/dx^2=12x-10where x =2:d^2y/dx^2=12x2-10=14If d^2y/dx^2>0 the point is a minimum. So, where x =2 the stationary point is a minimum.where x =-1/3:d^2y/dx^2=12x(-1/3)-10=-14If d^2y/dx^2<0 the point is a maximum. So, where x =-1/3 the stationary point is a maximum.

AK
Answered by Asha K. Maths tutor

9897 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

f(x) = (x-5)/(x^2+5x+4), express this in partial fractions and hence find the integral of f(x) dx between x=0 and x=2, giving the answer as a single simplified logarithm.


ABCD is a rectangle with sides of lengths x centimetres and (x − 2) centimetres.If the area of ABCD is less than 15 cm^2 , determine the range of possible values of x.


What is the gradient of the quadratic function y=3x²?


Find the equation of the tangent to the curve y=3x^2-7x+5 at the point (2, 3) .


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning