The area (in sq. units) of the part of the circle

Question:

The area (in sq. units) of the part of the circle $x^{2}+y^{2}=36$, which is outside the parabola $\mathrm{y}^{2}=9 \mathrm{x}$, is :

 

  1. $24 \pi+3 \sqrt{3}$

  2. $12 \pi-3 \sqrt{3}$

  3. $24 \pi-3 \sqrt{3}$

  4. $12 \pi+3 \sqrt{3}$


Correct Option: , 3

Solution:

Required area

$=\pi \times(6)^{2}-2 \int_{0}^{3} \sqrt{9} x d x-\int_{3}^{6} \sqrt{36-x^{2}} d x$

$=36 \pi-12 \sqrt{3}-2\left(\frac{x}{2} \sqrt{36-x^{2}}+18 \sin ^{-1} \frac{x}{6}\right)_{3}^{6}$

$=36 \pi-12 \sqrt{3}-2\left(9 \pi-3 \pi-\frac{9 \sqrt{3}}{2}\right)$

$=24 \pi-3 \sqrt{3}$

 

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