# Java Program to Compute a2+b2+c2 where Value of a, b and c are Given

In the previous article we have discussed Java Program to Compute (a+b+c)3 where Value of a, b and c are Given

In this program we are going to see how to compute a2+b2+c2  where value of a, b, and c are given

## Java Program to Compute a2+b2+c2 where Value of a, b and c are Given

The formula of a2 + b2 + c2 is given below.

a2 + b2 + c2  = (a + b + c)2 – 2(ab + bc + ca)

Now we will convert this into a valid Java expression.

Let x= a2+b2+c2

=  ((a+b+c)*(a+b+c))-2*((a*b)+(b*c)+(c*a))

Example:

Suppose a=2, b=2 and c=2, then

a2+b2+c2
= ((a+b+c)*(a+b+c))-2*((a*b)+(b*c)+(c*a))
= ((2+2+2)*(2+2+2))-2*((2*2)+(2*2)+(2*2))
= 12

Now let’s see different ways to compute a2+b2+c2

### Method-1: Java Program to Compute a2+b2+c2 where Value of a, b and c are Given By Using Static Input Value

Approach:

• Declare and initialize three integer variables say a, b and c.
• By using the formula compute a2+b2+c2
• Print the result.

Program:

class Main
{
public static void main(String[] args)
{
//declare the first integer variable with an integer value
int a= 4;
System.out.println("a= " +a);
//declare the second integer variable with an integer value
int b= 4;
System.out.println("b= "+b);
//declare the third integer variable with an integer value
int c= 2;
System.out.println("c= "+c);
//declare another integer variable and assigned the formulated value to it.
int d=((a+b+c)*(a+b+c))-2*((a*b)+(b*c)+(c*a));
System.out.println("(a2+b2+c2)= "+d);
}
}

Output:

a= 4
b= 4
c= 2
(a2+b2+c2)= 36

### Method-2: Java Program to Compute a2+b2+c2 where Value of a, b, and c are Given By Using Pow() Function

Approach:

• Declare three integer variables say a, b and c.
• Take the value of a and b as user input by using Scanner class.
• Then By using the formula compute a2+b2+c2
• Print the result.

Program:

import java.lang.Math;
import java.util.Scanner;
class Main
{
public static void main(String[] args)
{
//create object of scanner class.
Scanner sc=new Scanner(System.in);
System.out.print("a= ");
//Take the first input from the user.
int a= sc.nextInt();
System.out.print("b= ");
//Take the second input from the user.
int b= sc.nextInt();
System.out.print("c= ");
//Take the third input from the user.
int c= sc.nextInt();
//declare another integer variable and assigned the formulated value to it.
double  d=(Math.pow(a+b+c,2))-2*((a*b)+(b*c)+(c*a));
System.out.println("(a2+b2+c2)= "+(int)d);
}
}

Output:

a= 4
b= 4
c= 2
(a2+b2+c2)= 36

### Method-3: Java Program to Compute a2+b2+c2 where Value of a, b and c are Given By Using User Defined Method

Approach:

• Declare two integer variables say a, b and c.
• Take the value of a and b as user input by using Scanner class.
• Then call a user defined method say computeValue() and pass a, b and c as parameter.
• Then inside method by using the formula compute a2+b2+c2
• Print the result.

Program:

import java.util.Scanner;
class Main
{
public static void main(String args[])
{
//create object of scanner class.
Scanner sc=new Scanner(System.in);
System.out.print("a= ");
//Take the first input from the user.
int a= sc.nextInt();
System.out.print("b= ");
//Take the second input from the user.
int b= sc.nextInt();
System.out.print("c= ");
//Take the third input from the user.
int c= sc.nextInt();
//call the funtion
computeValue(a,b,c);
}
//define the method
public static void computeValue(int a, int b, int c)
{
//declare another integer variable and assigned the formulated value to it.
int d=((a+b+c)*(a+b+c))-2*((a*b)+(b*c)+(c*a));
System.out.println("(a2+b2+c2)= "+d);
}
}

Output:

a= 8
b= 10
c= 12
(a2+b2+c2)= 308

Interested in programming and want to excel in it by choosing the short ways. Then, practicing with the available Java Program list is mandatory.

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