Ho rieseguito javac aggiungendo -Xlint:unchecked ottenendo in risposta questa roba qua...
codice:
Note: RadiciNdiC.java uses unchecked or unsafe operations.Note: Recompile with -Xlint:unchecked for details.


G:\Lavoro e Universita\Java\radicindic>javac RadiciNdiC.java -Xlint:unchecked
RadiciNdiC.java:78: warning: [unchecked] unchecked call to add(E) as a member of
 the raw type ArrayList
                soluzioniR.add(anscosgdouble);
                              ^
  where E is a type-variable:
    E extends Object declared in class ArrayList
RadiciNdiC.java:79: warning: [unchecked] unchecked call to add(E) as a member of
 the raw type ArrayList
                soluzioniI.add(anssingdouble);
                              ^
  where E is a type-variable:
    E extends Object declared in class ArrayList
RadiciNdiC.java:90: warning: [unchecked] unchecked method invocation: method max
 in class Collections is applied to given types
            Object objR = Collections.max(soluzioniR);
                                         ^
  required: Collection<? extends T>
  found: ArrayList
  where T is a type-variable:
    T extends Object,Comparable<? super T> declared in method <T>max(Collection<
? extends T>)
RadiciNdiC.java:90: warning: [unchecked] unchecked conversion
            Object objR = Collections.max(soluzioniR);
                                          ^
  required: Collection<? extends T>
  found:    ArrayList
  where T is a type-variable:
    T extends Object,Comparable<? super T> declared in method <T>max(Collection<
? extends T>)
RadiciNdiC.java:91: warning: [unchecked] unchecked method invocation: method max
 in class Collections is applied to given types
            Object objI = Collections.max(soluzioniI);
                                         ^
  required: Collection<? extends T>
  found: ArrayList
  where T is a type-variable:
    T extends Object,Comparable<? super T> declared in method <T>max(Collection<
? extends T>)
RadiciNdiC.java:91: warning: [unchecked] unchecked conversion
            Object objI = Collections.max(soluzioniI);
                                          ^
  required: Collection<? extends T>
  found:    ArrayList
  where T is a type-variable:
    T extends Object,Comparable<? super T> declared in method <T>max(Collection<
? extends T>)
6 warnings
Potrei capire che ci potrebbero essere errori di codice, ma sia l'IDE che il prompt fanno capo alla stessa JVM, e l'IDE esegue regolarmente tutto.