equation of a line

Question

prove that the length of a line segment drawn from the point P (x0 , y0) and perpendicular to the line g: y = mx+n ( m ≠ 0 ) is | mx0 - y0 + n | / root m^2 + 1

evidence g: y=mx+n (m ≠ 0 ) suppose the perpendicular from P cut g on Q. Equation of the line PQ is ?

Answer 1

??????????? yu tri tu get DISTANS from a point tu a line ????????

if so, yu shood sae the "perpendikular line" go thru that point