Arnold & Arnold, Exercise 1.7 Solutions

Here are the solutions for Exercise 1.7 of Cambridge Mathematics 4 Unit textbook by Graham and Denise Arnold.
Remember that once you know the graph of $\displaystyle y=\sqrt{f(x)}$, then it is simply a matter of reflecting the square root curve in the $x$-axis to find the curve $\displaystyle y^2=f(x)$.

The reason for this is that if $\displaystyle y^2=f(x)$, then $\displaystyle y=\pm\sqrt{f(x)}$