The Curve C has equation y = 3x^4 - 8x^3 -3. Find the first and second derivative w.r.t x and verify that y has a stationary point when x = 2. Determine the nature of this stationary point, giving a reason for your answer.

The first derivative is otherwise denoted by dy/dx.dy/dx = 12x^3 -24x^2.The second derivative is denoted by d2y/dx2, otherwise known as the first derivative of the function dy/dx.d2y/dx2 = 36x^2 - 48x.A stationary point exists if dy/dx = 0 has a valid solution for x. dy/dx = 12x^3 -24x^2 = 0 ==> x = 0 and x = 2. (Check by substitution (dy/dx at x =2) and by finding the solution for dy/dx = 0).Substitute x =2 into d2y/dx2 = 36x^2 - 48x. The result is at x =2, d2y/dx2 is 48 > 0 and hence this stationary point is classified as a minima / minimum.

JB
Answered by Jemisha B. Maths tutor

5274 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

How do we work out the asymptotes of the graph y=1/x -5


(19x - 2)/((5 - x)(1 + 6x)) can be expressed as A/(5-x) + B/(1+6x) where A and B are integers. Find A and B


Find the gradient of the tangent to the line y=(x-2)^2 at the point that it intercepts the y-axis


Find the first derivative of 2x^3+5x^2+4x+1 (with respect to x)


We're here to help

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

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences