1 Write a method to calculate mathematical function f(x,y) = x+y? 2. Write a method to calculate mathematical function 3. The monthly payment of a mortgage of n months with monthly interest rater for a principal Is given by the mathematical formula pr(1+r)" (1 + r)" - 1 Write a method to calculate the monthly payment. 4. Write a method print3(Strings) to print a string three times in three lines with increasing indentation. For example, print3("Hello"); will print Hello Hello Hello 5. Lets be a string of odd length. Write a method remove(String s) to return a substring of swith the center character removed. For example, remove("Program") will return the string Proram". 6. A string variable fullName represents a full name such as Doe, John". Write a method shortName(String fullName) to return a string of first initial and last name, ex, 7. Doe" In java