How to find where a function has minimum value?

I have a function like this-

How can i find the value of δ for which, 'd(f(x+δ),g(x))' or 'δ_opt' will be minimum?

Here 'd(f(x+δ),g(x))' is a function.

Answer 1

[KSSV]

Have a look on fmincon this should help you to get what you want.

https://in.mathworks.com/help/optim/ug/fmincon.html