This question may become as an easy one but for us students is really important to understand a question before trying to answer it.
I am asked to
"deduce, using numerical derivation, an order 3 method to solve Initial-Value-Problems" $$y'=f(x,y)$$ $$y(x_0)=y_0$$
EDIT: My question is: "What would anyone understand from that question?"
Should I deduce a new method or an existing one (say RK3)?
Thanks in advance. Hope you can shed me some light to understand the question