The equation x2+y2+2x−4y×5=0 represents
a point
a pair of straight lines
a circle of non-zero radius
none of these
The radius of the given circle
=√12+(−2)2−5=0
Hence, the radius of the given circle is zero, which represents a point.
The equation of the circle passing through the point (1, 1) and having two diameters along the pair of lines x2−y2−2x+4y−3=0, is