(i)[5]
Find an expression for $\frac{dy}{dx}$ and show that the gradient of the curve at the point $(-1, 2)$ is $-\frac{5}{2}$.
(ii)[3]
Show that the curve has no stationary points.
(iii)[2]
Find the $x$-coordinate of each point on the curve where the tangent is parallel to the $y$-axis.