I am getting an error message when I try to include an initial condition for a second order ODE using DSOLVE:
Clear[y]
DSolve[{y''[x] + 7 y'[x] + 12 y[x] == 0, y[0] == -1, y'[0] == 0}, y[x], x]
DSolve::deqn: Equation or list of equations expected instead of True in the first argument {12 y[x]+7 (y^[Prime])[x]+(y^[Prime][Prime])[x]==0,y[0]==-1,True}.
This happened even after cutting and pasting an example from the documentation:
Clear[y] DSolve[{y''[x] + y[x] == 0, y[0] == 1, y'[0] == 1/3}, y , x]