Find dy/dx in terms of t for the curve defined by the parametric equations: x = (t-1)^3, y = 3t - 8/t^2, where t≠0

The first step is to recognise that, by the chain rule, dy/dx = dy/dt * dt/dx.
dy/dt and dt/dx can both be found by differentiating the functions given in the question, to give dy/dt and dx/dt. dt/dx is the inverse of dx/dt.
dy/dt = 3 + 16t^-3 by following the standard rule for differentiation ( y = x^n, dy/dx = nx^(n-1) )
dx/dt = 3(t-1)^2 by substitution. By saying the u = t-1, the function in y becomes x= u^3. Again using the chain rule, dx/dt = dx/du * du/dt. dx/du = 3u^2, and du/dt = 1. Therefore, dx/dt = 3(t-1)^2. Inverting this function gives dt/dx = 1/3*(t-1)^-2.
The final solution requires multiplying the functions for dy/dt and dt/dx to give dy/dx. dy/dx = dy/dt * dt/dx = (3 + 16t^-3) * 1/3*(t-1)^-2 = 3+16t^-3/3(t-1)^2

AC
Answered by Alex C. Maths tutor

20336 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Prove by contradiction that there is an infinite number of prime numbers.


Sketch the graph y = 2sin(4x)


Find the integral of 4x^2 - 10x + 1/(x^(1/2)), with respect to x, in its simplest form.


What are the main factors when deciding whether or not the Poisson distribution is a suitable model?


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