1. Open text editor and put this code
<?
echo $_SERVER['DOCUMENT_ROOT'];
?>
2. Save it as root.php for security purposes name it whatever you like - yourname.php
3. Drag and drop it in your public_html or root
4. Browse your site www.yoursite.com/root.php
5. it will show you the exact result.
6. Delete the root.php
Hope it will help.