IOS: Popover Position

I have this code:

if([self.popoverController isPopoverVisible])
{
    [self.popoverController dismissPopoverAnimated:YES];
    return;
}

UIViewController* popoverContent = [[UIViewController alloc]init];

popoverContent.view = tableView1.view; 

self.popoverController = [[UIPopoverController alloc]
                          initWithContentViewController:popoverContent];

[self.popoverController presentPopoverFromRect:CGRectMake(1200, 280, 50, 50) inView:self.view permittedArrowDirections:UIPopoverArrowDirectionDown animated:TRUE];
[[[popoverController contentViewController] view] setAlpha:1]; //alpha del contenuto del popover

[popoverContent release];

It works fine, but I can’t place a popover in the lower right corner, I'm trying to change the values ​​in [self.popoverController presentPopoverFromRect: CGRectMake (1200, 550, 100, 100) inView: self.view allowedArrowDirections: UIPopoverArrowDirectionDown animated: TRUE];

but I want this popover to be small in the lower right ... how can I do this?