複選題
3. (5%) Which statements are correct for the equation (2y2 + 3x)dx +2xydy =0?
(A) The differential equation is exact.
(B) It is possible to find an integrating factor so that the equation becomes exact.
(C) x=-y2 is one possible solution.
(D) x2y2+x3=1 is one possible solution.
(E) None of the above