Application: Determines the roots of a second degree equation

Create a program in Java, which receives the coefficients of an equation of the second degree and return their roots.

A quadratic equation is an equation where:
ax ² + bx + c = 0, with 'a' different from 0

Step 1:

The first part of the program receives three equation coefficients, which are 'a', 'b' and 'c' and will be represented by the type float.

Step 2:

An equation of the second degree is valid only if 'a' is different from 0. Then, if 'a' equals 0, the program should end.
That is, our program will happen within the 'if' that checks that 'a' is different from 0.

Step 3:

Determining the value of delta: delta = b ² - 4ac
Determining the square root of delta: sqrtdelta = (float) Math.sqrt (delta);

In Java, we calculate the square root of the number x with the method: Math.sqrt (x);
This method returns a type 'double'. How we use float in our coefficients, we use the cast '(float)' to turn the double to float.

Step 4:

If delta is greater than or equal to zero, the roots are given by:
root1 = (-b + sqrtdelta) / second
root2 = (-b - sqrtdelta) / second

Step 5:

If delta is less than zero, its roots will be complex and the roots are of the form:
root1 = (-b + i.sqrt (delta)) / 2a
root2 = (-b - i.sqrt (-delta)) / 2a

The output formatted as follows to become more legible, that is the same as the previous equations:
root1 = (-b) / 2a + i.sqrt (delta) / 2a
root2 = (-b) / 2a - i.sqrt (delta) / 2a

Java code:

import java.util.Scanner;

public class Bhaskara {
    public static void main(String[] args) {
        float a, b, c,      //coefficientes
              delta,        //delta
              sqrtdelta,    //squareroot of delta
              root1,root2;  //roots
        Scanner input = new Scanner(System.in);
        
        // Step 1: Receiving the coefficients
        System.out.println("Equation of second degree: ax² + bx + cx = 0");
        System.out.print("Enter with the value of a: ");
        a = input.nextFloat();
        System.out.print("Enter with the value of b: ");
        b = input.nextFloat();
        System.out.print("Enter with the value of c: ");
        c = input.nextFloat();
        
        // Step 2: checking if the equation is valid
        if(a != 0){
        
        // Step 3: getting the value of delta and calculating its square root
            delta = (b*b) - (4*a*c);
            sqrtdelta = (float)Math.sqrt(delta);
        
        // Step 4: if the root delta is greater than 0, the roots are real   
            if(delta >=0){
                root1 = (-b + sqrtdelta)/(2*a);
                root2 = (-b - sqrtdelta)/(2*a);
                System.out.printf("Roots: %.2f e %.2f", root1, root2);
            }
        // Step 5: If delta is less than 0, the roots will be complex
            else{
                delta = -delta;
                sqrtdelta = (float)Math.sqrt(delta);
                System.out.printf("Root 1: %.2f + i.%.2f\n", (-b)/(2*a), (sqrtdelta)/(2*a));
                System.out.printf("Root 2: %.2f - i.%.2f\n", (-b)/(2*a), (sqrtdelta)/(2*a));
                
            }
            
        }
        else{
            System.out.println("Coefficient 'a' invalid. There is not a second degree equation");
        }
    }

}