title: How can I code the program to accept not only uppercase but also lowercase first letter?
body: <p>For example, if I run the program and type in sin, it shows error. When I write down Sin, it's ok. For example, if I run the program and type in sin, it shows error. When I write down Sin, it's ok. For example, if I run the program and type in sin, it shows error. When I write down Sin, it's ok. For example, if I run the program and type in sin, it shows error. When I write down Sin, it's ok.</p>
  <pre><code>/*************************************************************
                              Pavel Kivilša
                                 EKF-21
                          1 laboratorinis darbas
                                 2021-11
  *************************************************************/
  
  #define _CRT_SECURE_NO_WARNINGS
  #include &lt;string.h&gt;
  #include &lt;stdio.h&gt;
  #include &lt;stdlib.h&gt;
  #include &lt;math.h&gt;
  
  enum Functions { Floor, Round, Ceil, Sin, Cos, Cosh, Exp, Tan, Tanh, Sinh, Log, Log10, Sqrt, Pow, Trunc, Help };
  enum Functions function_name;
  
  int main(int argc, char* argv[]) {
      float number, number2;
      char* function[16] = { &quot;Floor&quot;, &quot;Round&quot;, &quot;Ceil&quot;, &quot;Sin&quot;, &quot;Cos&quot;, &quot;Cosh&quot;, &quot;Exp&quot;, &quot;Tan&quot;, &quot;Tanh&quot;, &quot;Sinh&quot;, &quot;Log&quot;, &quot;Log10&quot;, &quot;Sqrt&quot;, &quot;Pow&quot;, &quot;Trunc&quot;, &quot;Help&quot; };
  
      char name[6];
      printf(&quot;Enter a math function: &quot;);
      scanf(&quot;%s&quot;, name);
  
      for (function_name = 0; function_name &lt;= 15; function_name++) {
          if (strcmp(function[function_name], name) == 0) {
              break;
          }
      }
  
  
      switch (function_name) {
      case Floor:
          printf(&quot;Enter the value of floor: &quot;);
          scanf(&quot;%f&quot;, &amp;number);
          printf(&quot;Floor of %.2f is equal to %.2f\n&quot;, number, floor(number));
          break;
      case Round:
          printf(&quot;Enter the value of round: &quot;);
          scanf(&quot;%f&quot;, &amp;number);
          printf(&quot;Round of %.2f is equal to %.2f\n&quot;, number, round(number));
          break;
      case Ceil:
          printf(&quot;Enter the value of ceil: &quot;);
          scanf(&quot;%f&quot;, &amp;number);
          printf(&quot;Ceil of %.2f is equal to %.2f\n&quot;, number, ceil(number));
          break;
      case Sin:
          printf(&quot;Enter the value of sin: &quot;);
          scanf(&quot;%f&quot;, &amp;number);
          printf(&quot;Sin of %.2f is equal to %.2f\n&quot;, number, sin(number));
          break;
      case Cos:
          printf(&quot;Enter the value of cos: &quot;);
          scanf(&quot;%f&quot;, &amp;number);
          printf(&quot;Cos of %.2f is equal to %.2f\n&quot;, number, cos(number));
          break;
      case Cosh:
          printf(&quot;Enter the value of cosh: &quot;);
          scanf(&quot;%f&quot;, &amp;number);
          printf(&quot;Cosh of %.2f is equal to %.2f\n&quot;, number, cosh(number));
          break;
      case Exp:
          printf(&quot;Enter the value of exp: &quot;);
          scanf(&quot;%f&quot;, &amp;number);
          printf(&quot;Exp of %.2f is equal to %.2f\n&quot;, number, exp(number));
          break;
      case Tan:
          printf(&quot;Enter the value of tan: &quot;);
          scanf(&quot;%f&quot;, &amp;number);
          printf(&quot;Tan of %.2f is equal to %.2f\n&quot;, number, tan(number));
          break;
      case Tanh:
          printf(&quot;Enter the value of tanh: &quot;);
          scanf(&quot;%f&quot;, &amp;number);
          printf(&quot;Tanh of %.2f is equal to %.2f\n&quot;, number, tanh(number));
          break;
      case Sinh:
          printf(&quot;Enter the value of sinh: &quot;);
          scanf(&quot;%f&quot;, &amp;number);
          printf(&quot;Sinh of %.2f is equal to %.2f\n&quot;, number, sinh(number));
          break;
      case Log:
          printf(&quot;Enter the value of log: &quot;);
          scanf(&quot;%f&quot;, &amp;number);
          printf(&quot;Log of %.2f is equal to %.2f\n&quot;, number, log(number));
          break;
      case Log10:
          printf(&quot;Enter the value of log10: &quot;);
          scanf(&quot;%f&quot;, &amp;number);
          printf(&quot;Log10 of %.2f is equal to %.2f\n&quot;, number, log10(number));
          break;
      case Sqrt:
          printf(&quot;Enter the value of sqrt: &quot;);
          scanf(&quot;%f&quot;, &amp;number);
          printf(&quot;Sqrt of %.2f is equal to %.2f\n&quot;, number, sqrt(number));
          break;
      case Pow:
          printf(&quot;Enter the value of pow: &quot;);
          scanf(&quot;%f&quot;, &amp;number);
          printf(&quot;Enter the second value of pow: &quot;);
          scanf(&quot;%f&quot;, &amp;number2);
          printf(&quot;%.2f to the power of %.2f is equal to %.2f\n&quot;, number, number2, pow(number, number2));
          break;
      case Trunc:
          printf(&quot;Enter the value of trunc: &quot;);
          scanf(&quot;%f&quot;, &amp;number);
          printf(&quot;Trunc of %.2f is equal to %.2f\n&quot;, number, trunc(number));
          break;
      case Help:
          printf(&quot;The following functions can be used: Floor, Round, Ceil, Sin, Cos, Cosh, Exp, Tan, Tanh, Sinh, Log, Log10, Sqrt, Pow, Trunc.\n&quot;);
          break;
      default:
          printf(&quot;Function not found, try again by typing in Help.\n&quot;);
          break;
      }
      return 0;
  }
  </code></pre>