همون کد مسعود هست به زبان سی
#include<stdio.h>
#include<math.h>
using namespace std;
main(){
float a, b;
char opt;
int n;
scanf("%f %f %c %i",&a,&b,&opt,&n);
double DeltaX = (b-a)*1.0/n;
float sum = 0;
switch (opt)
{
case '1':
for (int i=1; i<=n; i++)
sum += sin(a + (2*i-1)/2 * DeltaX) * DeltaX;
break;
case '2':
for (int i=1; i<=n; i++)
sum += cos(a + (2*i-1)/2 * DeltaX) * DeltaX;
break;
}
printf("result is %f",sum);
}