What is a parametric equation?

A parametric equation is one that is defined in terms of a single parameter, usually called t.
This means that, instead of the standard geometric equation, where y and x are defined by each other, e.g. y=3x, they are defined by this other parameter, e.g. y=t, x=t/3, where t is the input.
Both of the examples given are the same, merely in a different format, it's important to understand how to rearrange a parametric equation into a geometric equation.
All you have to do is rearrange to find t on it's own, and then equate the two:
y=t,
x=t/3, 3x=t=y, y=3x.

JB

Related Maths A Level answers

All answers ▸

Show that 2tan(th) / (1+tan^2(th)) = sin(2th), where th = theta


Find dy/dx of the curve x^3+5xy-2y^2-57=0


Find the gradient of the tangent and the normal to the curve f(x)= 4x^3 - 7x - 10 at the point (2, 8)


Given that Sin(A) = 1/sqrt(3), show that Tan(A) = 1/sqrt(2)