

That is C1 and C2 are identical
so value of determinant =0
hence area of triangle =0
Equation of the line which perpendicular to the given line is x - y + k = 0
Since this line passes through (2,-3)
2-(-3) + k = 0
This implies k= -5
Hence the equation og the line is x - y =5
On solving the lines x+y=0 and x-y=5, we get the point of intersection as x = 5/2 and y = -5/2
Hence (5/2,-5/2) is the coordinates of orthogonal projection.



