Equation of the circle of radius √2 containing the point (3, 1) and touching the line |x-1|=|y-1|, is
x2+y2-3x+4y+7=0
x2+y2-6x+2y-4=0
x2+y2-6x-2y+8=0
none of these
The common chord of the circle x2+y2+4x+1=0 and x2+y2+6x+2y+3=0 is