Calculus
posted by Liz .
Convert to a rectangular equation by eliminating the parameter:
x=sin(theta)
y=(cos theta)^2

from y = cos^2 Ø
y = 1  sin^2 Ø
sin^2 Ø = 1y
sinØ = √(1y)
so sinØ = x and sinØ = √(1y) , so
x = √(1Y)
or
x^2 = 1y