Appendix B - Graphing Utilities - B.1 The Viewing Rectangle - B.1 Assess Your Understanding - Page B3: 14

$X[-90,30,10]$ by $Y[-50,70,10]$

1. Examine the given coordinates, we can find the minimum and maximum of each direction as $X, -80, 20$ and $Y, -40, 60$ 2. Set scale=10 and the window 10 unit larger each direction to cover the above numbers, we can get the viewing window as $X[-90,30,10]$ by $Y[-50,70,10]$ where the first number in the bracket represents the minimum value, the second number the maximum value, and the last number the scale.