Find the critical point of f(x,y)=x2+y2−4x−2y+5f(x,y) = x^2 + y^2 - 4x - 2y + 5f(x,y)=x2+y2−4x−2y+5.
(2, 1)(2,\; 1)(2,1)
(4, 2)(4,\; 2)(4,2)
(0, 0)(0,\; 0)(0,0)
(1, 2)(1,\; 2)(1,2)