Which problems are suitable for ode 45?

I dont understand that ode 45's purpose ?

why cant i find same answer with quad command ?

[James Tursa]

Your question is too generic. Maybe you could start by describing the problem you are trying to solve, and the issues you are currently having.

Answer 1

[Walter Roberson]

If you had a function of one variable, that involves only the direct derivative (without the function itself) and it had no mass variable, and you arranged to get the boundary conditions right, then quad() could potentially substitute for ode45(). For example dxdt = @(dt) dt .* sin(dt) could potentially be doable, but not dt.*sin(t) . Oh, and you couldn't do any event conditions either.

In any case involving mixed levels of derivatives, or multiple variables, or mass variables, or event conditions then quad() is not sufficient to be able to calculate the results.

[Sevval Zengin]

Thank you so muchhh