Answer
Graph a, $y=x^2$, is in red.
Graph b, $y=x^2-2$, is in blue.
Graph c, $y=x^2+2$ is in green.
Work Step by Step
Using a TI-84, press 'Y=' in the top left corner. Then enter your equations and press 'GRAPH' in the upper right-hand corner. Your graphs should look like the example above.