4. Set f(x, y) = x2 + 2y2. Which of the following must be true?
(A) f(x, y) is concave upward on the line $y = -x (B) the relative minimum of f(x, y) subject to the constraint x + y = 1 is
(C) the absolute minimum of f(x, y) on its domain does not exist
(D) the minimum rate of change of f(x, y) at the point P(1, -1) is
3. Which of the following must be true?
(A) The series converges for all p≠0$
(B) The series
converges absolutely
(C) The series
converges
(D) The series
diverges
2. Which of the following must be true?
(A)
(B)
(C)
(D)