# Determine the Area of surface when y = 2 Sqrt x is rotated about the y axis [attempt]

• Mar 8th 2011, 12:13 PM
Riazy
Determine the Area of surface when y = 2 Sqrt x is rotated about the y axis [attempt]
Hello guys the problems is to determine the area of y = 2 Sqrt X when it is rotaded about the y axis, you can see my progress in my uploaded paper.

I would need some help finishing it.

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• Mar 8th 2011, 01:24 PM
poirot
Quote:

Originally Posted by Riazy
Hello guys the problems is to determine the area of y = 2 Sqrt X when it is rotaded about the y axis, you can see my progress in my uploaded paper.

I would need some help finishing it.

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complete the square
• Mar 8th 2011, 11:52 PM
Riazy
could you show me how?
• Mar 9th 2011, 01:52 AM
mr fantastic
Quote:

Originally Posted by Riazy
could you show me how?

integrate Sqrt&#91;x&#94;2 &#43; x&#93; - Wolfram|Alpha

Click on Show steps.

But the above is pointless since you are not using the correct formula for finding the surface (should be dx/dy NOT dy/dx inside the square root).