Finding area between two curves Polar Coordinates

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The discussion focuses on finding the area between the curves defined by polar equations r = 3sinθ and r = 1 + sinθ. The intersection points of these curves are identified at π/6 and 5π/6. A proposed approach involves integrating the difference of the two functions, but there is confusion regarding the correct integrand and the formula for polar area. Participants confirm that the integral can be computed using these limits and suggest using Wolfram Alpha for verification. The correct area calculation yields approximately 1.369705.
PsychonautQQ
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Homework Statement


Find the area inside the circle r = 3sinθ and outside the carotid r = 1 + sinθ




The Attempt at a Solution


Alright so I graphed it and found that they intersect at ∏/6 and 5∏/6.
I can't think of a good way to approach the problem. The carotid has some of it's area beneath the x-axis otherwise I would take the area of the 3sinθ - the area of the other one. Will it work if set the limits of integration to pi/6 and 5pi/6 and take the integral of (3sinθ - (1+sinθ)? I'm a bit lost
 
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PsychonautQQ said:

Homework Statement


Find the area inside the circle r = 3sinθ and outside the carotid r = 1 + sinθ




The Attempt at a Solution


Alright so I graphed it and found that they intersect at ∏/6 and 5∏/6.
I can't think of a good way to approach the problem. The carotid has some of it's area beneath the x-axis otherwise I would take the area of the 3sinθ - the area of the other one. Will it work if set the limits of integration to pi/6 and 5pi/6 and take the integral of (3sinθ - (1+sinθ)? I'm a bit lost

Yes, that all seems reasonable. Just compute your integral and you're done.
 
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I got 1.369705. Is there any online integral doer I can use to check my work?
 
PsychonautQQ said:
I got 1.369705. Is there any online integral doer I can use to check my work?

Yes, that's the correct answer. Wolfram alpha is good for checking your work afterwards.
 
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PsychonautQQ said:

Homework Statement


Find the area inside the circle r = 3sinθ and outside the carotid r = 1 + sinθ




The Attempt at a Solution


Alright so I graphed it and found that they intersect at ∏/6 and 5∏/6.
I can't think of a good way to approach the problem. The carotid has some of it's area beneath the x-axis otherwise I would take the area of the 3sinθ - the area of the other one. Will it work if set the limits of integration to pi/6 and 5pi/6 and take the integral of (3sinθ - (1+sinθ)? I'm a bit lost

NO. That's the wrong integrand. Look up the formula for polar area.
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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