Question 1022412
{{{graph(400,400,-2,5,-4,3,-2x+1,-1+sqrt(0.01-(x-4)^2),-1-sqrt(0.01-(x-4)^2))}}}


You want to <i>MEASURE</i> the length of the segment joining the point to the given line.  The segment is perpendicular to y=-2x+1.


{{{graph(400,400,-2,5,-4,3,-2x+1,-1+sqrt(0.01-(x-4)^2),-1-sqrt(0.01-(x-4)^2),x/2-3)}}}