Perpendicular to AB is x-y+5=0
y=x+5
Standard equation of line is y=m x+c where slope is m
so slope of line perpendicular to AB = 1
so slope of AB = -1
equation of line AB is: y=-x+c
AB passes through (1,-2)
thus, -2=-1+c
c = -1
Equation of line AB with slope(-1) : y=-x-1 or x+y+1=0
Posted by
Deependra Verma