Answer
$$y=\dfrac{6-3x}{2}$$ $$ \text{ Straight Line }$$
Work Step by Step
We have: $x=2 \sin^2t \implies \sin^2 t=\dfrac{x}{2}$ and $y= \cos^2t \implies \cos^2 t=\dfrac{y}{3}$
Now, use the identity $$\sin^2 t+\cos^2 t=1 \dfrac{x}{2}+\dfrac{y}{3}\\ 1=\dfrac{3x+2y}{6} \\y=\dfrac{6-3x}{2}$$
This shows a straight line.