I have this problem in Java. Please add comments

Functional Interfaces and Lambda Expressions Using IntCalculator.java from chapter 10 (page 684) of the Gaddis text, implement both an Anonymous Inner Class, and a Lambda Expression that returns the results of the following expressions: // 1. given int parameter x, return the value of the polynomial return x2 + 2x + 4; // 2. given two double parameters x and y, return x to the y return xy; // use Math.pow // 3. given a double parameter, r, return ?*r2 return Math.PI * r * r; // 4. given int parameter x, return x!, if x<= 0, just return 1 Notice that there should be both an anonymous inner class implementation, AND a lambda expression implementation for each of the 4 expressions. Include a separate class that has a public static main method that tests your four expression handlers. Place all of your java files into a single zip file and upload to Canvas.