title: When i try to give 3 inputs to my program , it needs 4 to run properly. Why is that?
body: <pre><code>#include &lt;stdio.h&gt;
  #include &lt;stdlib.h&gt; 
  #define f(x) (1 / (x*x+1))
  
  
  
  int main(){
      double a,b,h,x,y;
  
      printf("Enter a, b, h:  ");
      scanf(" %lf %lf %lf " , &amp;a, &amp;b, &amp;h);
  
  // I ask for 3 inputs but the programm needs 4 to run...why is that?
  
  
      x = a;
  
       while(x&lt;b)
       {
  
          y = f(x);
          printf("%lf %lf \n", x ,y );
          x +=h;
  
       }
  
  
      system("Pause");
      return(0);  
  
  }
  </code></pre>