$\begin{align}(i)&y=x^2+2\\[5pt] &y=x^2+4\\[5pt] (ii)&y=x^2+2\\[5pt] &y=x^2\\[5pt] \end{align}$
$\begin{align}(i)&y=-x^2\\[5pt] &y=-x^2+3\\[5pt] (ii)&y=-x^2\\[5pt] &y=-x^2-3\\[5pt] \end{align}$
$\begin{align}(i)&y=2x^2+5\\[5pt] &y=2x^2+11\\[5pt] (ii)&y=2x^2-1\\[5pt] \end{align}$

By studying this lesson you will be able to

Find the gradient of the graph of a straight line.