• Source
    1. #include <stdio.h>
    2. #include <math.h>
    3.  
    4. float f(float);
    5. float a;
    6. float b;
    7. float x;
    8. float h;
    9. float sum;
    10. int n;
    11. int j;
    12.  
    13. float first;
    14. float second;
    15. int main() {
    16. a = 0;
    17. b = 2;
    18. n = 8;
    19. h = (b - a) / n;
    20.  
    21. sum = (h / 3) * (f(a) + f(b));
    22.  
    23. printf("%f\n", sum);
    24.  
    25. for (j = 1; j <= ((n / 2.0f) - 1); j++) {
    26. first = first + (2.0f / 3.0f) * h * f(a + (2 * j * h));
    27. }
    28. printf("first sum: %f\n",first);
    29.  
    30. for (j = 1; j <= (n / 2.0f); j++) {
    31. second = second + (4.0f / 3.0f) * h * f(a + ((2 * j - 1) * h));
    32. }
    33. printf("second sum: %f\n",second );
    34.  
    35. sum = sum + first + second;
    36. printf("The value of the integral is: %f\n", sum);
    37. return 0;
    38. }
    39.  
    40. float f(float x) {
    41. float value;
    42. value = x * x * (log(x * x + 1));
    43. return value;
    44. }