Question 58056
if the slope is "undefined", then the line is a vertical and goes through the x-point of the ordered pair.
X ..... Y
-2 ... -5
-2 ... -4
-2 ... 0
-2 ... 16

It doesnt matter the Y co-ordinate.
{{{ drawing( 200, 200, -5, 5, -5, 5,
       grid( 1 ),
       green( line( -2, -5, -2, 5 ))
)
}}}