Given y = 2sin(θ) and x = 3cos(θ) find dy/dx.

The function is defined parametrically so we usually approach these questions using chain rule.Recall that: dy/dθ * dθ/dx = dy/dx So we will need to differentiate each expression individually then multiply them together.Differentiating the first with respect to θ we get:(1)   dy/dθ = 2cos(θ) ,then the expression for x gives us: dx/dθ = -3sin(θ) , We can then remember that differentials behave as fractions so we can flip both sides to get:(2)  dθ/dx = -1/3sin(θ) . Remembering chain rule we can multiply (1)*(2) to get dy/dx: dy/dθ * dθ/dx = 2cos(θ) * -1/3sin(θ) --> dy/dx = -2cos(θ)/3sin(θ)

Answered by Jacob C. Maths tutor

4402 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

How do you integrate e^x cos x


Find the equation of the tangent to the curve y=x^3-4x^2+2 at the point (3,-7)


How do you differentiate using the chain rule?


How do you know if a stationary point on a curve is a maximum or minimum without plotting the graph?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2024

Terms & Conditions|Privacy Policy
Cookie Preferences