Write function isPalindrome that checks if a given string (case insensitive) is a palindrome.
```racket
In Racket, the function is called palindrome?
(palindrome? "nope") ; returns #f
(palindrome? "Yay")  ; returns #t
```
def is_palindrome(s):
    return True if s.lower() == "".join(reversed(s.lower())) else False

def is_palindrome(s):
    return True if s.lower() == "".join(reversed(s.lower())) else False
