Nevermind I totally got it now, sorry to waste anyones time!
Your mistake is in the line above. The expression raised to the 3/2 power in your antiderivative is x + 1, not x so both your terms above are incorrect. After evaluating the antiderivative at the two endpoints you should have (2/3)[(2 + 1)^(3/2) - 1^(3/2)].
yeah I seen that, I just did alot of correcting to that post, so please take a look at it again because it has changed
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