First we note that the line passes through the points (0,-2) and (0,-4), so, to find the slope of a parallel line, we need to find the slope of the first line:
[tex]m=\frac{y_2-y_1}{x_2-x_1}=\frac{-4-(-2)}{0-0}=\frac{-2}{0}[/tex]
As we can see, the slope is not defined on our original line, so a slope to a paralle line should be a non defined slope
