If f(x+2y,x−2y)=xy, then f(x,y) equals
If f(x+2y, x-2y)=xy, then f(x, y) equals
Let f(x,y)=√x2+y2+√x2+y2−2x+1+√x2+y2−2y+1+√x2+y2−6x−8y+25∀x,yϵR, then