A typical graphing calculator has a height to width ratio of

\frac{2}{3} .

Therefore, the graphing calculator will display a square window if the height and width satisfy this ratio.

\frac{Height}{Width} = \frac{2}{3}

We are asked to determine if a window with the following parameters is a square.

- 8 \leq x \leq 7 - 3 \leq y \leq 7

To do that, let's first find the height

y

and width

x

of the given viewing window.

Width : Height : 7 - (- 8) = 15 7 - (- 3) = 10

Now we check if the ratio of height and width is equal to

\frac{2}{3} .

\frac{Height}{Width} = \frac{2}{3}

SubstituteII

$Height = 10$ , $Width = 15$

\frac{1 0}{1 5} = ? \frac{2}{3}

ReduceFrac

$\frac{a}{b} = \frac{a / 5}{b / 5}$

\frac{2}{3} = \frac{2}{3} ✓

We got a true statement. This means that the viewing window is a square.

Extra

Setting Up the Window in a Graphing Calculator

To set up the window in a graphing calculator, first press $WINDOW .$ To see the screen form the example, set Xmin to $- 8,$ Xmax to $7,$ Ymin to $- 3,$ and Ymax to $7 .$

Now press $GRAPH$ to see the viewing window.

As we can see, the tick marks are spaced the same on both axes. Therefore, this is a square viewing window.

Exercise 1 Page 102

Hints

Check the answer

Practice exercises

Asses your skill

Extra