Home > Algebra > Horizontal and Vertical Line Graphs

What is the slope of a line that is parallel to a vertical line?

Answer 1

Any line that is parallel to a vertical line is also vertical and has undefined slope.

A vertical line is given by the equation #x = a# for some constant #a#. This line passes through the points #(a, 0)# and #(a, 1)#.

Its slope #m# is given by the formula:

#m = (Delta y) / (Delta x) = (y_2 - y_1) / (x_2 - x_1) = (1 - 0) / (a - a) = 1/0#

which is undefined.

By signing up, you agree to our Terms of Service and Privacy Policy

Answer 2

Eva Abramson

A vertical line and all lines parallel to it have undefined slopes

Note that if a line is vertical, all lines parallel to it are also vertical.

For any two points #(x_1,y_1)# and #(x_2, y_2)# on a line the slope is defined as #(y_2-y_1)/(x_2-x_1)#

BUT if the line is vertical #x_1 = x_2# for all points on the line and therefore the definition of the slope would require dividing by zero (which is undefined).

By signing up, you agree to our Terms of Service and Privacy Policy

Answer 3

Avery Alexander

The slope of a line that is parallel to a vertical line is undefined.

By signing up, you agree to our Terms of Service and Privacy Policy

Answer 4

Ethan Adkins

The slope of a line that is parallel to a vertical line is undefined.

By signing up, you agree to our Terms of Service and Privacy Policy

Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.