How do you write the equation of the vertical line passing through the point (-2,1)?

2 Answers
May 2, 2016

x = -2


This is a special case of the equation of a line in that it's slope is undefined and it is parallel to the y-axis. The line passes through all points in the plane with the same x-coordinate and has equation
y = c where c is the value of the x-coord.
In this case the line passes through (-2 ,1) and it's equation is x = -2
graph{0.001y-2=x [-10, 10, -5, 5]}

May 2, 2016

#x = -2#


All vertical lines only have an #x-#intercept, where they cross the #x#-axis. They are therefore written in the from #x = .....#

Seeing that the x-value of the point is -2, it means that this is the value of #x# we need to use for the equation of the vertical line.