#include <stdio.h>
#include <stdlib.h>
void afficheIntervalle(float res1, float res2)
{
    printf("[%f , %f]\n",res1 - sqrt(res2),res1 + sqrt(res2));
}

int main()
{
    int i;
    float res1, res2;
    float res = 0;
    for(i = 0; i < 10; i++ )
{
    res1 = res1 + i;
    res2 = res2 + i * i;
}
    res1 = 10;
    res2 = res2 /10 - res1 * res1;
    afficheIntervalle(res1,res2);
}