﻿ Java - Solve quadratic equations

## Java Conditional Statement: Exercise-2 with Solution

Write a Java program to solve quadratic equations (use if, else if and else).

Test Data
Input a: 1
Input b: 5
Input c: 1

Pictorial Presentation:

Sample Solution:

Java Code:

``````import java.util.Scanner;
public class Exercise2 {

public static void main(String[] Strings) {

Scanner input = new Scanner(System.in);

System.out.print("Input a: ");
double a = input.nextDouble();
System.out.print("Input b: ");
double b = input.nextDouble();
System.out.print("Input c: ");
double c = input.nextDouble();

double result = b * b - 4.0 * a * c;

if (result > 0.0) {
double r1 = (-b + Math.pow(result, 0.5)) / (2.0 * a);
double r2 = (-b - Math.pow(result, 0.5)) / (2.0 * a);
System.out.println("The roots are " + r1 + " and " + r2);
} else if (result == 0.0) {
double r1 = -b / (2.0 * a);
System.out.println("The root is " + r1);
} else {
System.out.println("The equation has no real roots.");
}

}
}
```
```

Sample Output:

```Input a: 1
Input b: 5
Input c: 2
The roots are -0.4384471871911697 and -4.561552812808831
```

Flowchart:

Java Code Editor:

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﻿

## Java: Tips of the Day

IsPowerOfTwo

Checks if a value is positive power of two.

To understand how it works let's assume we made a call IsPowerOfTwo(4).

As value is greater than 0, so right side of the && operator will be evaluated.

The result of (~value + 1) is equal to value itself. ~100 + 001 => 011 + 001 => 100. This is equal to value.

The result of (value & value) is value. 100 & 100 => 100.

This will value the expression to true as value is equal to value.

```public static boolean isPowerOfTwo(final int value) {
return value > 0 && ((value & (~value + 1)) == value);
}
```

Ref: https://bit.ly/3sA5d4I

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