To write the equation of a line perpendicular to the one whose equation is given, we should first determine its slope.
y=-5
We can see that there is no x-variable. This means that the slope is and the line is a horizontal line.
y=-5 ⇔ y= * x-5
According to the Slopes of Perpendicular Lines Theorem, the line perpendicular to the horizontal line is a vertical line. Since it also has to pass through the point P( 6,-3), the equation of the line is x= 6. Let's graph the lines on a coordinate plane.
By looking at the graphs of the lines, we can see that they are indeed perpendicular.
