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## Homework Statement

Hello! I have been given a problem of ordinary differential equations to be solved in matlab by ode45. The equations are on a sheet but you can see what equations i put in. I did as the teacher instructed but matlab gives me a error message. Can you see what I misunderstood? :/

'prim' is the vector of derivatives so I think I have written the problem in the right structure.

## The Attempt at a Solution

First m-file, the function file (name blandning.m):

PHP:

```
function prim = blandning(tid, x1, x2, x3, s, q, w);
s = 1;
q = 1;
w = 0.1610; %Parameters
prim = [s*(x2 - x2*x1 + x1 - q*x1^2); -s^(-1)*(x2 - x1*x2 + x3); w*(x1 - x3)];
end
```

PHP:

```
clc
clear all
s = 1;
q = 1;
w = 0.1610; %Parameters
x1 = 30;
x2 = 1;
x3 = 30; %intialconditions
tf = 10; %final time
x0 = [x1; x2; x3]; %intial vector
tid = [0, tf];
[t, x] = ode45(blandning, t, x0, [], s, q, w);
plot(t, x)
```

*"??? Input argument "x2" is undefined.*

Error in ==> blandning at 7

prim = [s*(x2 - x2*x1 + x1 - q*x1^2); -s^(-1)*(x2 - x1*x2 + x3); w*(x1 - x3)];

Error in ==> Huvud at 17

[t, x] = ode45(blandning, t, x0, [], s, q, w);

"

Error in ==> blandning at 7

prim = [s*(x2 - x2*x1 + x1 - q*x1^2); -s^(-1)*(x2 - x1*x2 + x3); w*(x1 - x3)];

Error in ==> Huvud at 17

[t, x] = ode45(blandning, t, x0, [], s, q, w);

"

Thanks for all help possible!

/ Hymne