can you help me with this? thanks

3. We do not have general Existence Uniqueness Theorems for BVPs, as a result we can sometimes nd many solutions, or no solutions, to otherwise simple looking DES. Find all solutions to the BVP y\" + 4y(m) = 0 with the following B05. (3) 9(0) = 1,y(7T/4) = -1, ('0) 11(0) = 1,y(7r/2)= 1, (C) 9(0) = 1,y(7r/2)= 1