I am trying to find a solution to this system of differential equations but the program gives the same output without any messages. I would like help. Please find the Mathematica code posted here. a and d are Constants, I=sqrt(-1)$
S1 = I y' == Cos[a t] Exp[- I d t] x;
S2 = I x' == Cos[a t] Exp[ I d t] y;
S = {S1, S2};$I=\sqrt{-1}$
DSolve[S, {y, x}, t]
S1 = I y' == Cos[a t] Exp[- I d t] x;
S2 = I x' == Cos[a t] Exp[ I d t] y;
S = {S1, S2};
DSolve[S, {y, x}, t]