Write the equation of a line that contains the point (9,3) and is perpendicular to the x-axis

Answer 1

Hi Natalia,

We want a line containing the point (9, 3) that’s perpendicular to the x-axis.

For me, personally, the first step would be to sketch the graph, just to get a sense of what’s going on. Since our line is supposed to be perpendicular to the x-axis, it should be vertical. This means that y can be anything, but x has to stay fixed at the value 9. Can you see from the picture why this is true?

Therefore, the equation for our line is simply x = 9. Hope this makes sense! (Based on what I’ve said, could you draw and then find the equation of a line through (9, 3) that’s parallel to the x-axis?)

Kiran

Answer 2

Answer 3

Since the line is perpendicular to the x-axis, it is vertical. Every vertical line has equation x = c, where c is a constant. Since the point (9,3) is on the line, an equation of the line is x = 9.

Answer 4

x=9

a vertical line is perpendicular to the x axis

x never changes value