Java Exercise 1

Objective:

1. Introduction to Java
2. How to compile Java code
3. Simple arithmetic problems solving

Activity 1:

Take two inputs from user (keyboard) length and breadth of rectangle. Compute the area of rectangle given by: area = length*breadth

Solution:

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int length = 0;
        int breadth = 0;
        int area = 0;

        Scanner scanner = new Scanner(System.in);
        
        System.out.println("Enter Length and Breadth of Rectangle");

        length = scanner.nextInt();
        breadth = scanner.nextInt();

        area = length * breadth;

        System.out.println("The Area is = " + area);

        scanner.close();
    }
}

Activity 2:

Write Java code to solve the second-degree equation aX^2 + bX + c= 0 for any real numbers a, b and c. The program takes the values of a, b and c as input from the user, and calculates X.

Note: real numbers are taken in float.

Solution:

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        float a = 0;
        float b = 0;
        float c = 0;

        Scanner scanner = new Scanner(System.in);

        System.out.println("Enter three Real Numbers a, b and c: ");

        a = scanner.nextFloat();
        b = scanner.nextFloat();
        c = scanner.nextFloat();

        float eq1;
        float sq;
        float eq2;
        float eq3;

        eq1 = (b * b) - (4 * a * c);
        sq = (float) Math.sqrt(eq1);

        eq2 = (-b - sq) / (2 * a);
        System.out.println("The First value of X is = " + eq2);

        eq3 = (-b + sq) / (2 * a);
        System.out.println("The Second value of X is = " + eq3);

        scanner.close();
    }
}