**Finding Equations of Horizontal and Vertical Lines**

The Problem |

Find equations of vertical
and horizontal lines passing through the point (8,5). Then graph the lines. |

The equation of a vertical
line has the form **x = k**, where k is some number. Since the x-coordinate
of the given point is 8, the equation of the vertical line passing through the
point is:

**x
= 8**.

In order to graph this line on the calculator, press 2nd, then PRGM [DRAW], and select 4:Vertical. Then press the 8 key and then ENTER, and the line will appear as shown below.

The**
viewing rectangle** was preset to [-10,10,1] by [-10,10,1].

The equation of a horizontal
line has the form** y = k**, where k is some number. Since the y-coordinate
of the given point is 5, the equation of the horizontal line passing through
the point is

**
y = 5**.

In order to graph this
line, press
and enter **5** for .
Now press **ZOOM**, then select **6:Standard**, and the graph should appear
as shown below.

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