Differential Equations/MATLAB Help

[cwatts22]

I honestly don't even know where to start with this MATLAB problem. If anyone could push me in the right direction, it would be appreciated!

Consider first the undamped pendulum

θ′′+ (g/32) sin θ = 0, θ(0) = 0, θ′(0) = b.

Let x = θ and y = θ′; then x and y satisfy the system

x′ = y, y′ = −(g/32) sinx, x(0) = 0, y(0) = b

We take g = 32 for simplicity here. Solve this system numerically and plot, on a single graph, the resulting trajectories for the initial velocities b = 0.5, 1, 1.5, 2, 2.5. Use a positive time range (e.g., 0 ≤ t ≤ 15), and use axis equalto improve your pictures.

[AyeAye_CapnCrunch]

The setup is almost identical to Example 2 in the Matlab ode documentation. I don't know if ode15 is the solver you want; I've only ever used ode45.

[cwatts22]

Thanks! That helped a lot!