Parametric equationsEdexcel A-Level Maths: Flashcards

What these 12 flashcards ask

What is a parametric equation?
How do you convert parametric equations to Cartesian form?
Cartesian equation of x=r\cos t, y=r\sin t?
Centre and radius of x=a+r\cos t, y=b+r\sin t?
Cartesian form of x=5t, y=\frac5t?
Cartesian form of x=5t, y=3t^2?
How do you find where a parametric curve meets the y-axis?
How do you find where a parametric curve meets a given line?
Why does the domain of t matter?
What part of the circle is x=4\cos t, y=4\sin t for 0\le t\le\pi?
Solve \cos t=\frac12 for 0\le t<2\pi.
What should you do with a solution for t outside the stated domain?

Exam questions on Parametric equations

A curve $C$ has parametric equations $x=2t+1$ , $y=4t^2-3$ , where $t$ is a real number.
Find the coordinates of the point where $C$ crosses the $y$ -axis.2 marks
A curve $D$ has parametric equations $x=-2+4\cos t$ , $y=3+4\sin t$ , for $0\le t<2\pi$ .
Find the values of $t$ , for $0\le t<2\pi$ , at the points where $D$ meets the line $x=0$ .2 marks
A curve $H$ has parametric equations $x=3t$ , $y=\frac{12}{t}$ , where $t\ne0$ .
Find a Cartesian equation of $H$ in the form $xy=k$ , and state the values that $x$ cannot take.3 marks

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).