Is the line with equation x = 4 horizontal or vertical? What is the slope of this line?

Question

jdoe0001 · Answer

x = 4  means

$ \begin{array}{llll}
y = 10 & x = 4\
y = 100 & x = 4\
y = -10 & x = 4\
y = -100 & x = 4\
y = 1,000,000 & x = 4\
y = \pm \infty& x= 4

\end{array}$
so  |dw:1379105849793:dw|

jdoe0001 · Answer

what's the slope for this line, well, slope is rise/run
run will be $\bf x_2-x_1$   but notice, that x is always the same value, in this case 4
so the run is $\bf 4-4 = 0$, that makes our denominator in the equation $\bf \cfrac{rise}{run} \implies \cfrac{y_2-y_1}{x_2-x_1} \qquad  \color{red}{undefined}$

goformit100 · Answer

"Welcome to OpenStudy. I can guide regarding this useful site; ask your doubts from me, for it you can message me. Please use the chat for off topic questions. And remember to give the helper a medal, by clicking on "Best Answer". We follow a code of conduct, ( http://openstudy.com/code-of-conduct ). Please take a moment to read it."