- #1

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[tex]y = ln x, y = 1, y = 2, x = 0;[/tex] about the x-axis

since there are 3 "y"s

I'm not sure how to use

[tex]V = \int_{a}^{b} {A(x)}{dx}[/tex]

Thank you in advance~

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- Thread starter sonzai
- Start date

- #1

- 1

- 0

[tex]y = ln x, y = 1, y = 2, x = 0;[/tex] about the x-axis

since there are 3 "y"s

I'm not sure how to use

[tex]V = \int_{a}^{b} {A(x)}{dx}[/tex]

Thank you in advance~

- #2

arildno

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However, here's how you could proceed analytically:

Since for x<e, ln(x)<1, and will tend to negative infity as x trundles towards 0, it follows that this segment cannot be part of our region.

Thus, for 0<=x<=e, the cross-section lies between y=1 and y=2.

When x=e^2, ln(e^2)=2, so that for e<=x<=e^2, we have that our region lies between y=ln(x) and y=2.

Use this info to complete the problem.

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