複選題1. (5%) Which are the possible solutions of the differential equation =y2-9? (A) y=3 (B) y=-3 (C) (D)(E)

4. (5%) Consider the equationwiththe boundary conditions y(0)=0.y(π)=π.Which statements are correct? (A) The particular solution is yP =-x. (B) The general solution is y=ex sinx+x. (C) There is a unique solution to this boundary-value problem. (D) This differential equation is homogencous. (E) None of the above.