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

5383 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Prove the Quotient Rule using the Product Rule and Chain Rule


Sine Rule


How would you derive y = function of x; for example: y = 3x^3 + x^2 + x


Write sqrt(50) in the form Asqrt(50) where A is an integer


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:

© 2025 by IXL Learning