Area between 2 polar equations

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SUMMARY

The discussion focuses on calculating the area between two polar curves: \( r = 6 \) and \( r = 6 - 6\sin(\theta) \). The area is determined using the formula \( A = \frac{1}{2} r^2 \theta \). The correct limits for integration are identified as \( \pi \) to \( 2\pi \), which can be confirmed by graphing the curves and finding their intercepts. The user initially proposed incorrect limits but was guided to verify their calculations through plotting.

PREREQUISITES
  • Understanding of polar coordinates and equations
  • Familiarity with integration techniques in calculus
  • Knowledge of graphing polar equations
  • Ability to apply area formulas for polar curves
NEXT STEPS
  • Study the derivation and application of the area formula for polar coordinates
  • Learn how to graph polar equations effectively
  • Explore methods for finding intersections of polar curves
  • Practice calculating areas between various polar curves
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Students studying calculus, particularly those focusing on polar coordinates, as well as educators looking for examples of area calculations between polar curves.

Zack K
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Homework Statement


Find the area of the region that lies inside the first curve and outside the second curve.
##r=6##
##r=6-6sin(\theta)##

Homework Equations


##A=\frac {1} {2}r^2\theta##

The Attempt at a Solution

\[/B]
If I'm correct, the area should just be ##\frac {1} {2}\int_{0}^{2\pi} 6^2 d\theta - \frac {1} {2}\int_{0}^{2\pi} (6-6sin(\theta))^2 d\theta##. If that's the case then I'm probably making simple error calculating it.

EDIT: I just realized by graphing that the range is between π to 2π. How would I figure that out? Would it be just by setting both equations equal and finding intercepts?
 
Last edited:
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Zack K said:

Homework Statement


Find the area of the region that lies inside the first curve and outside the second curve.
##r=6##
##r=6-6sin(\theta)##

Homework Equations


##A=\frac {1} {2}r^2\theta##

The Attempt at a Solution

\[/B]
If I'm correct, the area should just be ##\frac {1} {2}\int_{0}^{2\pi} 6^2 d\theta - \frac {1} {2}\int_{0}^{2\pi} (6-6sin(\theta))^2 d\theta##. If that's the case then I'm probably making simple error calculating it.

EDIT: I just realized by graphing that the range is between π to 2π. How would I figure that out? Would it be just by setting both equations equal and finding intercepts?
Plotting is the way to go, but I don't think your proposed limits are correct. Plot a few easy points and you will see. Remember you want outside the second curve.
 

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