# include<conio.h>

# include<stdio.h>

# include<stdlib.h>

# include<math.h>

int k,i=0,m=0,flag=0;

int coef[10]={0};

float x1=0,x2=0,t=0;

float fx1=0,fdx1=0;

what is the benefits if the variables are defined outside of the function ,just after #include

thanks!!