>>775
#include <stdio.h>
double f(double x){
return x*x;
}
double integral(double a, double b, double h){
int n = (int)((b - a) / h);
double sum = (f(a) + f(b)) / 2;
for(int i = 1; i < n; i++){ sum += f(a + i*h); }
return sum * h;
}
int main(){
printf("%f", integral(0, 3, 0.1));
}