How do you find the slope of the line $x=-7$ ?

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Answer 1 · 2015-08-01T23:22:52

This is a vertical line so has undefined slope.

If a line passes through points $(x_1, y_1)$ and $(x_2, y_2)$ then its slope $m$ is given by the formula:

$m = (Delta y)/(Delta x) = (y_2 - y_1) / (x_2 - x_1)$

In the case of the line $x=-7$ , let us use the distinct points $(-7, 0)$ and $(-7, 1)$ in this formula to find:

$m = (y_2 - y_1) / (x_2 - x_1) = (1 - 0) / (-7 - (-7)) = 1/0$ which is undefined.

How do you find the slope of the line x=-7x=-7?