solving rlc circuit using ode45

i have homework to solve rlc circuit using ode45 i tried this code and the question is how to plot Vl1 anyone can help me please and if there is any mistake in this code

function RLC=homework(t,x)
R1=20;R2=30;L1=4*10^-3;L2=2*10^-3;C=0.004;u=100;
RLC(1)=(R1/L1)*(x(1))+(1/L1)*(x(2))-(1/L1)*u;
RLC(2)=-(R2/L2)*(x(2))+(1/L2)*(x(3));
RLC(3)=(-1/C)*(x(1))-(1/C)*(x(2));
RLC=RLC';

   [t,x]=ode45('homework',[0 10],[2;2;2]);

[James Tursa]

You are missing a minus sign on the first rhs term on the x1dot line:

RLC(1) = -(R1/L1)*(x(1)) + (1/L1)*(x(2)) - (1/L1)*u;

[sami alzeq]

thanks

Answer 1

[Aquatris]

If you were to use the code;

    [t,y] = ode45(@homework,t,[0 0 0]');

the y here is your i1, i2, and vc.

From here you should know how to get desired Voltages (Kirschof law etc.).

The subplot command will be used as;

   subplot(4,1,1),plot(t,Vl1) % "subplot(4,1,2)" means there will be 
   subplot(4,1,2),plot(t,Vr2) % 4 rows and 1 column in total for 
   subplot(4,1,3),plot(t,Vr1) % the plots and this one is the 2nd 
   subplot(4,1,4),plot(t,Vc)  % plot

Similar thing for the currents.

In part 4, you just need to replace u in the function with the sine wave.

Is there any particular question you have other than these?