﻿ C : Calculate the sum of the series [ x - x^3 + x^5 + …]

# C Exercises: Calculate the sum of the series [ x - x^3 + x^5 + ......]

## C For Loop: Exercise-24 with Solution

Write a program in C to find the sum of the series [x - x^3 + x^5 + ......].

This C program calculates the sum of the series x - x^3 + x^5 - ... up to a specified number of terms. The user inputs the value of x and the number of terms n. The program then uses a loop to compute each term of the series, alternating the sign and increasing the exponent by 2 for each subsequent term. Finally, the program sums the terms and prints the result.

Sample Solution:

C Code:

``````#include <stdio.h> // Include the standard input/output header file.
#include <math.h>  // Include the math functions header file.

void main()
{
int x, sum, ctr; // Declare variables to store input and intermediate results.

int i, n, m, mm, nn; // Declare loop control variables and intermediate results.

printf("Input the value of x :"); // Prompt the user for input.
scanf("%d", &x); // Read the value of 'x' from the user.

printf("Input number of terms : "); // Prompt the user for input.
scanf("%d", &n); // Read the value of 'n' from the user.

sum = x; // Initialize 'sum' to 'x' as the first term in the series.
m = -1;  // Initialize 'm' to -1.

printf("The values of the series: \n"); // Print a message.

printf("%d\n", x); // Print the first term of the series.

for (i = 1; i < n; i++) // Loop to calculate subsequent terms in the series.
{
ctr = (2 * i + 1); // Calculate the power of 'x' using the given formula.
mm = pow(x, ctr); // Calculate the value of 'x' raised to the power 'ctr'.
nn = mm * m;      // Multiply 'mm' with 'm'.
printf("%d \n", nn); // Print the calculated term.
sum = sum + nn;      // Add the term to the running sum.
m = m * (-1);        // Toggle the value of 'm' between -1 and 1.
}

printf("\nThe sum = %d\n", sum); // Print the final sum.
}
```
```

Output:

```Input the value of x :2
Input number of terms : 5
The values of the series:
2
-8
32
-128
512

The sum = 410
```

Flowchart:

C Programming Code Editor:

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