Error when plotting a graph

Hello, I am trying to plot the solution to the ordinary second order linear inhomogeneous differential equation:

x''(t)= -x + sin(1.1*t).

I am able to get the solution using the dsolve command, but when I try plotting it using 'plot(x,Solution)', I get an error message saying: 'Warning error updating parametrized function line the following error was reported evaluating the function..' and I can't scroll more to see the full error message.

Any help would be great!

Answer 1

[Star Strider]

Use fplot if you have R2016a or later, ezplot otherwise.

[Louis Sharma]

Hi thanks for replying so quick! I forgot to mention that I also tried using fplot but got the same error message..

[Star Strider]

My pleasure!

Try this:

syms x(t) t 
Dx = diff(x);
Eqn = diff(x,2) == sin(1.1*t) - x;
Xs = dsolve(Eqn, Dx(0) == 0, x(0) == 0)                 % Include Initial Conditions

figure
fplot(Xs, [0 10])
grid

[Louis Sharma]

Hi this is great! Thank you so much. This might be a bit much, but since I'm new to Matlab and would like to learn it, could you tell me why my first code didn't work?

Once again thank you!

clear all 
syms x(t)
t_min = 0;
t_max= 10;
s = 1.1;
dx = diff(x);
cond_1= x(0) ==1;
cond_2 = dx(0)==0;
conds = [cond_1 cond_2];

ODE= diff(x,t,2) == -x+sin(s*t);
Sol = dsolve(ODE, conds)
Solution = simplify(Sol)


figure 
fplot(x,Solution)

[Star Strider]

As always, my pleasure!

You did not call fplot correctly. Compare your call to it, and mine.

Call it as:

fplot(Solution, [0 10])

and it works.

[Louis Sharma]

Amazing! This was really helpful!

[Star Strider]

Thank you!