C/math.h/erf

    
//Header file: #include <math.h>  
//Declaration: float erff(float arg); 
               double erf(double arg); 
               long double erfl(long double arg);  
  #include <math.h>
  #include <stdio.h>
  int main(void)
  {
     printf("Value of e to the first: %f.", erf(1.0));
 
  }
         
/*
Value of e to the first: 0.842701.*/