Parametric equations and locus Q's (1 Viewer)

[puffynutty]

1. The variable point ( 3t, 2t 2 ) lies on a parabola. Find the Cartesian equation for this parabola.

2.A curve has parametric equations x = t/2 , y = 3t² . Find the Cartesian equation for this curve.

 

[tommykins]

1.
x = 3t
y = 2t^2

t = x/3

y = 2.(x/3)^2 = 2x^2/9
9y = 2x^2 -> x^2 = 9y/2

2. x = t/2, y = 3t^2
t = 2x
y = 3(2x)^2 = 3.4x^2 = 12x^2
y/12 = x^2

 

[puffynutty]

thanks, i knew how to get the answer but i didn't know what cartesian form was.

 

[tommykins]

cartesian is in the form of y = whatever (with x's of course)

 

[puffynutty]

ah ok i have learnt that thanks