Isolating coefficients from a long exponential function

Questions
, ,
1

I would like to isolate the coefficients from the solution of this ODE, into a list:

sol = DSolve[{y'''[x] + y''[x] + y[x] == 0, y'''[0] == 1, y''[0] ==1,
              y'[0] == 0}, y[x], x]
soln= TrigToExp[sol];
Cases[soln, a_ Exp[b_ t] :> {b, a}]

Since the coefficients are long and messy.
The given attempt with “Cases” did not succeed.
How can I do that?

Thanks

2

soln = TrigToExp[y /. sol[[1]]] // Simplify // ExpandAll
Cases[soln, c_ Exp[__] → c]

3

You probably mean

sol = DSolve[{y'''[x] + y''[x] + y[x] == 0, y'''[0] == 1, y''[0] == 1,    y'[0] == 0}, y[x], x]

soln = TrigToExp[sol];

Cases[soln, a__ Exp[b__ x] :> {b, a}, \[Infinity]]
4

Thanks Roland! That worked!