Answer
(1) $x=t, y=\sqrt t \ (t\geq 0)$
(2) $x=t^2, y= t \ (t\geq 0)$
(3) $x=-t, y=\sqrt {-t} \ (t\leq 0)$
Other answers are possible.
Work Step by Step
(1) $x=t, y=\sqrt t \ (t\geq 0)$
(2) $x=t^2, y= t \ (t\geq 0)$
(3) $x=-t, y=\sqrt {-t} \ (t\leq 0)$
