Question 736732
given:

{{{P}}}=({{{-8}}},{{{4}}}), slope {{{undefined}}}

The slope of a {{{vertical}}} line is {{{undefined}}} because anything divided by zero is undefined.

All you need to do is plot the point {{{P}}} and draw a line parallel to y-axis through {{{x=-8}}}


{{{drawing(600,600,   -10, 10, -10, 10,  blue(line(-8,10,-8,-10)), grid(0),circle(-8,4,0.2),circle(-8,0,0.2),
graph( 600,600,   -10, 10, -10, 10)) }}}