Hello purplerainYou will have to set the question out more carefully if you want help here. I assume that this is an integration question (in which case it should be in the Calculus Form), but your use of notation is very unclear.

I can't see how you get . It's , not . And in any event, when you take the square root, you'll get , not .

The only way you can get is if the expression is . Is that what you mean?

The answer you quote, , suggests it may be a definite integral. Can we see the original question, please?

Grandad