If mr,1/mr,r=1,2,3,4, are four pairs of values of x and y that satisfy the equation x2+y2+2gx+2fy+c=0, then the value of m1m2m3m4 is

If mr,1/mr satisfy the given equation x2+y2+2gx+2fy+c=0, then mr2+1mr2+2gmr+2fmr+c=0⇒ mr4+2gmr3+cmr2+2fmr+1=0Now, roots of given equation are m1,m2,m3,m4. The product of roots m1m2m3m4= Constant term  Coefficient of mr4=11=1