For each of the following sets of parametric equations, determine the relationship between x and y.

1. $x\left(t\right) = \cos t$ and $y\left(t\right) = \sin t$

   Hint (a):

   See the hints for problem 10-84.

2. $x\left(t\right) = \cos t^{3}$ and $y\left(t\right) = \sin t^{3}$

3. $x\left(t\right) = t^{4} − 2t^{2}$ and $y\left(t\right) = t^{2}$

   Hint (c):

   $x = \left(t^{2}\right)^{2} − 2\left(t^{2}\right)$