This is what I do for those situations:
I don't start the html element with class 'hide', but I put style="display: none".
This is because bootstrap jquery modifies the style attribute and not the classes to hide/unhide.
Example:
<button type="button" id="btn_cancel" class="btn default" style="display: none">Cancel</button>
or
<button type="button" id="btn_cancel" class="btn default display-hide">Cancel</button>
Later on, you can run all the following that will work:
$('#btn_cancel').toggle() // toggle between hide/unhide
$('#btn_cancel').hide()
$('#btn_cancel').show()
You can also uso the class of Twitter Bootstrap 'display-hide', which also works with the jQuery IU .toggle() method.