how do i clear recent serches on google using my ipad ?

Clear Safari's cache : Settings > Safari > Clear Cookies And Data and also Clear History

And then close Safari completely and when you re-open it your search history should have gone : from the home screen (i.e. not with Safari 'open' on-screen) double-click the home button to bring up the taskbar, then press and hold any of the apps on the taskbar for a couple of seconds or so until they start shaking, then press the '-' in the top left of the Safari app to close it, and touch any part of the screen above the taskbar so as to stop the shaking and close the taskbar.