- #1

ver_mathstats

- 260

- 21

- Homework Statement
- The homework statement is given below in a picture.

- Relevant Equations
- ODE 45 Matlab

I got the answer for this question but I was wondering about stepsize when it comes to a problem like this? Is there a way to change the step size? Would my step size change in line 20, or would it change in line 3? I tried changing line 3 to be

`t=0:100:17.1`

but then I get a error message, so would I just be changing line 20? x = linspace (0,17.1,10000); so 10 000 would be a fixed step size? I don't know how to proceed from this so any help would be appreciated.
Matlab:

```
mu = 0.012277471;
mu_hat = 1 - mu;
t = [0, 17.1];
u1_0 = 0.994;
u1_prime_0 = 0;
u2_0 = 0;
u2_prime_0 = -2.001585106379082522420537862224;
y_0 = [u1_0, u1_prime_0, u2_0, u2_prime_0]';
% y’ = f(y);
% y = (u1, u1’, u2, u2’)T;
Func = @(t, y)[
y(2);
y(1) + 2*y(4) - mu_hat*(y(1)+mu)/(((y(1)+mu)^2+y(3)^2)^(3/2))...
- mu*(y(1)- mu_hat)/(((y(1)-mu_hat)^2+y(3)^2)^(3/2));
y(4);
y(3) - 2*y(2) - mu_hat*y(3)/(((y(1)+mu)^2+y(3)^2)^(3/2)) - ...
mu*y(3)/(((y(1)-mu_hat)^2+y(3)^2)^(3/2))];
solution = ode45(Func, t, y_0,[10^-2,0]);
x = linspace (0,17.1,10000);
y1 = deval(solution,x,1);
y2 = deval(solution,x,3);
plot (y1,y2);
print -depsc ’odeorbit.eps’
```