This question is an example question in the book. Basically it applies Ito's lemma to a function Y.
The thing i don't understand is why when we use dy/dt, we do not consider d(z(t))/dt, since y=e^-(mu*t)*Z(t), when we want to find dy/dt, do we also need to consider Z'(t) as well? But why the book doesn't consider Z'(t)?
Below is the formula for Ito's lemma, in case you don't know.
The thing i don't understand is why when we use dy/dt, we do not consider d(z(t))/dt, since y=e^-(mu*t)*Z(t), when we want to find dy/dt, do we also need to consider Z'(t) as well? But why the book doesn't consider Z'(t)?
Below is the formula for Ito's lemma, in case you don't know.