What equation represents a line parallel to the y-axis?

A line parallel to the y-axis is a vertical line. In terms of an equation, a vertical line passing through the x-coordinate `a` can be represented as `x = a`.

To understand why this equation represents a line parallel to the y-axis, let's break it down:

- In the equation `x = a`, the variable `x` represents the x-coordinate of any point on the line. Since `x` is always equal to `a`, it means that no matter what value `y` takes, `x` will always be constant.

- This indicates that for every value of `y`, there exists just one possible value of `x`, which means the line does not change its position horizontally. Hence, it is vertical.

In summary, an equation in the form `x = a` represents a line parallel to the y-axis. The value `a` determines the x-coordinate at which the line passes through.

A line parallel to the y-axis is a vertical line. In general, the equation of a vertical line is given by x = a, where "a" is the x-coordinate of any point on the line.

a line parallel to the y-axis has the same x-value for all coordinate pairs.

What is the equation for the y-axis?

x=0

so, any line x=k will be parallel to it:

x=-10
x=20
x=pi/3
x=10^100
. . .