Configuration options for relational algebra evaluator "ra.jar"
That RA tool does not have an option to output the SQL queries.

However, the mapping from relational algebra to SQL is pretty much trivial (except for division), can be easily found with a web search, and is something you should have learned in your course.

If you want to find out how RA handles this, look into the file RAXNode.java.
The various classes derived from RAXNode each implement one relational algebra operation; the method toPrintString shows the RA operation, while genViewDef generates the corresponding SQL command.
For example:

public static class PROJECT extends RAXNode {
    public String toPrintString() {
        return "\\project_{" + _columns + "}";
    }
    public String genViewDef(DB db) {
        return "SELECT DISTINCT " + _columns + " FROM " + getChild(0).getViewName();
    }
}
...
public static class INTERSECT extends RAXNode {
    public String toPrintString() {
        return "\\intersect";
    }
    public String genViewDef(DB db) {
        if (db.getDriverName().equals("com.mysql.jdbc.Driver")) {
            // MySQL doesn't support INTERSECT, so we need a workaround.
            ...
        } else {
            return "SELECT * FROM " + getChild(0).getViewName() +
                " INTERSECT SELECT * FROM " + getChild(1).getViewName();
        }
    }
}