How do I find dy/dx for a given equation, once this is found how do I find the value of x such that dy/dx = 0.

From a given equation y = mx + c. Finding dy/dx allows us to see the gradient of the curve. In order to do this we can follow the formula:When y = xn , dy/dx = nxn-1 . Let us use this in a real scenario. Say we are given the equation y = 3x2 - 6x + 4. We can break this down into stages. First let us differentiate the 3x2. Here the n = 2. So we bring the 2 to the front and subtract 1 from the power: so differentiating 3x2 we have 6x. Now we do the same for -6x. Here the n = 1 so we bring to the 1 to the front and subtract 1 from the power: so differentiating -6x we have -6 (-6x0 = -6). Differentiating a constant results to cancelling that constant so differentiating the 4 results in 0 (as the gradient of a constant function is always 0). Putting all this together we have dy/dx = 6x -6. Now to find the value of x such that dy/dx = 0. We have our dy/dx as shown. We then set dy/dx = 0 and solve the equation. We therefore have 6x - 6 = 0. This implies that 6x = 6. So therefore x =1.

SA
Answered by Sebastian A. Maths tutor

30465 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

The function f(x) is defined by f(x) = 1 + 2 sin (3x), − π/ 6 ≤ x ≤ π/ 6 . You are given that this function has an inverse, f^ −1 (x). Find f^ −1 (x) and its domain


Solve, giving your answer to 3 s.f. : 2^(2x) - 6(2^(x) ) + 5 = 0


A curve has parametric equations x=t(t-1), y=4t/(1-t). The point S on the curve has parameter t=-1. Show that the tangent to the curve at S has equation x+3y+4=0.


The function f is defined as f(x) = e^(x-4). Find the inverse of f and state its domain.


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