Question

Write a program to find the sum of the following series:
1 - 2^1 + 3^2 - 4^3 + 5^4- ... upto n terms​

Answer 1

Required Answer:-

Question:

Write a program to find out the sum of the following series.

1 - 2¹ + 3² - 4³ + 5⁴. . . . . . .

Solution:

Here is the program.

import java.util.*;

public class Sum {

public static void main(String[] args) {

Scanner sc=new Scanner(System.in);

System.out.print("Enter limit - ");

int n=sc.nextInt();

double s=0.0;

for(int i=1;i<=n;i++) {

double x=Math.pow(i, i-1);

if(i%2==1)

s+=x;

else

s-=x;

}

System.out.println("Sum is: "+s);

sc.close();

}

}

Explanation:

• Nth term of the series is in the form of n^(n - 1). For example, 1 = 1⁰, 2 = 2¹ and so on. First term is added to the sum while the next term is subtracted from it. We have created a variable x that contains the nth term of the series. If the value of 'i' is odd, then it adds the value of x to the sum or else, it subtracts the value from the sum.

Output is attached.