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Math Help - Area between two circles

  1. #1
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    Area between two circles

    I would like to know if my thinking on the problem is correct. I need to find the area between the circles r = sin(\theta) and r = cos(\theta)

    After I graphed the 2 circles I looked at them and realized that the area between them is symmetric so I only need to find one half of it and multiply it by 2. So I figured that if I just took the circle r = sin(\theta) and did the integral 2* \frac12 \int_0 ^\frac\pi4 sin^2(\theta)d\theta I would get the area bounded between the two circles. In the end I got \frac\pi8 - \frac14

    Could someone tell me if I am correct. Thank you.
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  2. #2
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    That answer is correct for the integral given.
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  3. #3
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    I know that the integral is correct, but I would like to know if my thinking that lead to that integral is correct as well.
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  4. #4
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    I believe so. I know I answered this question a month or so ago but I can't remember what the outcome was.

    Integrating the sin function from 0 to pi/4 is the right idea.

    The answer is reasonable too so I think you have it.

    The thread I did whenever is at physicsforums.com.
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  5. #5
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  6. #6
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    Awesome, thank you.
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