I am new to this technology
can anybody tell me How do i set back button image on navigation form using Xamarin forms.
and hide back button text.
The only way to do this is to override the NavigationBar on each particular OS you have.
In WP8 it doesn't matter as you shouldn't have any nav bar. Android you will need to look at the ToolBar and on iOS is the NavigationBar.
Since you want to change the image I am assuming Android.
Have a look at http://blog.xamarin.com/android-tips-hello-toolbar-goodbye-action-bar/ that should give you some ideas on how to start interacting with the Toolbar.
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