you did everything fine until the very end ... you added when you should have subtracted.
I have worked this question on finding the volune of revolution.. but i think there is something wrong..
I have posted the question + my works up to the answer.
Can anyone check it and let me know if its good please?
I have to submit it in 12 hours time.
Should i use this formula ?if yes how do i apply it here...
Thanks in advance..