Answer to Question #9157 in Analytic Geometry for jayasurya
what is the equation of line passing through (1,2) and perpendicular to equation y=7
y=7 is a horizontal straight line. So required line is vertical (because it is perpendicular to horizontal) general equation of vertical line is x=Const. It's given that the required line is passing through (1,2) so required equation is x=1.