Big Ideas Math Geometry, 2014
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Big Ideas Math Geometry, 2014 View details
5. Equations of Parallel and Perpendicular Lines
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Exercise 15 Page 160

The line parallel to a vertical line must be vertical as well.

Equation: x=- 2
Graph:

Practice makes perfect
The lines in the form x=a are vertical. Thus, the given line, x= - 5, is vertical and all points laying on this line have an x-value equal to - 5. The line parallel to a vertical line must be vertical as well. This means we can write a general equation for all lines parallel to the given equation. x=a

We also want the parallel line to pass through the point ( - 2,6). Therefore, a must be equal to - 2. x= - 2 Finally, we can verify our answer by graphing both lines on the same coordinate plane. If they are parallel, they will never intersect.

We can see by looking at the graphs of the functions that they are indeed parallel.