title: how can i call a function that takes an argument in racket?
body: <p>I am still new in racket language. 
  I am implementing a switch case in racket but it is not working.
  So, I shift into using the equal and condition. I want to know how can i call a function that takes input. for example: factorial(n) function
  I want to call it in :</p>
  
  <pre><code>(if (= c 1) (factorial (n))
  </code></pre>