Question

what is the equation for the line that is perpendicular to the x-axis and passes through the point (4, -7)?

Answer 1

Step-by-step explanation:

perpendicular means to cross at a right angle (90 degrees).

so, any line perpendicular to the x-axis is parallel to the y-axis.

and any line parallel to the y-axis has only a defining x value. all points on that line have the same x value (while any value for y from -infinity to +infinity is valid).

the y-axis itself is

x = 0

the specified point here has an x value of 4.

so, the line we are looking for is

x = 4

to point out : this is NOT a function, because for the same x value we get more than 1 valid y values.