Question 5997
It would be x = 3. Yes, that can be a line.


If an equation's got an undefined slope, it's automatically a vertical line. Remember when you calculated slope by saying {{{ m = (y[2] - y[1])/(x[2]-x[1]) }}}. A vertical line results if {{{ x[2] = x[1] }}} forcing the denominator of the slope formula to be 0, which we can't have (that is, we can't have a zero denominator in math).


If you take all the points of a vertical line, their x-coordinates are all the same. If (3,-8) lies on that line, then so does (3,100) and (3,-195.2226). I just chose those two y values because it wouldn't matter. Since the y value can be ANYTHING and its choice doesn't affect that x value, your equation simply boils down to x = 3 in this case, because the x-coordinate given to you was 3.