The output will be 3.6 if you use

cout << setiosflags(ios::showpoint) << setprecision (2) << num

<< endl;

And output will be 3.60 if you use

cout << setiosflags(ios::fixed) << setprecision(2) << num

<< endl;

if you use cout << setiosflags(ios::fixed||ios::showpoint)

<< setprecision(2) << num << endl; , the output will be

3.60.