i have a2004 sorento at 35mph and above there is a bad vibration coming from rear end could it be drive shaft or rear end

Never looked under a Sorento, but if it does have a drive shaft, it probably needs new universal joints. Have read consumer posts, and some people had to replace the entire drive shaft. Never specified why. If you replace the universal joints and still have vibration issues, you may have a slightly bent drive shaft. If this was bought second hand or was a salvage title, most likely the drive shaft is bent.