Week 5 Classwork Solutions

WeekFiveCW.java

/**
 * This class contains the solutions to
 * the Week 5 classwork exercises.
 */
public class WeekFiveCW {

    public static void main(String[] args) {

        // Problem 1
        System.out.println("\nClasswork Problem 1\n"); // to separate problems

        double num1 = 3; // change these to see what happens
        double num2 = 5.5;
        System.out.println("\tSum: " + add(num1, num2));
        System.out.println("\tDifference: " + subtract(num1, num2));
        System.out.println("\tProduct: " + multiply(num1, num2));
        System.out.println("\tQuotient: " + divide(num1, num2));

        // Problem 2
        System.out.println("\nClasswork Problem 2\n"); // to separate problems

        double radius = 1.8; // change this to see what happens
        System.out.println("\tArea: " + circleArea(radius));

    }

    /* Problem 1: Arithmetic Operations
        - Make four custom methods: add, subtract, multiply, & divide
        - Each method should:
            - Take two double parameters (x & y)
            - Compute the arithmetic operation with the numbers
            - Return the result
        - Call each method in the main method
        - Print the answers
    */
    public static double add(double x, double y) {
        return x + y;
    }

    public static double subtract(double x, double y) {
        return x - y;
    }

    public static double multiply(double x, double y) {
        return x * y;
    }

    public static double divide(double x, double y) {
        return x / y;
    }

     /* Problem 2: Circle Area
        - Create a method called circleArea() that calculates the area of
          a circle
            - It should have 1 parameter - the radius r
            - It should return the area
            - It should use one or more Math class methods
     */
    public static double circleArea(double r) {
        return Math.PI * Math.pow(r, 2);
    }

}