MATLAB: Matlab dsolve function issue with format.

MATLAB

I tried to do
>> eqn = '2*D2x + 2.2*Dx + 0.4*x = 0';
>> sol = dsolve(eqn);
>> pretty(sol)
/ / sqrt(41) 11 \ \
C1 exp| -t | -------- + -- | | + C2
\ \ 20 20 / /
/ / sqrt(41) 11 \ \
exp| t | -------- - -- | |
\ \ 20 20 / /
How can I get the answer as C1exp(-0.280*t) +C2 exp(-0.870t) rather than the format shown above. Thanks.

Best Answer

  • My (R2020a) version requires slightly different symbolic convetions.
    Try this:
    syms x(t)
    Dx = diff(x);
    D2x = diff(Dx);
    eqn = 2*D2x + 2.2*Dx + 0.4*x == 0;
    sol = dsolve(eqn);
    sol = vpa(sol,4);
    pretty(sol)
    producing:
    C1 exp(-0.8702 t) + C2 exp(-0.2298 t)
    .