JEE Class main Answered

Above itegration can be performed in polar coordinates ( r ,  ) over a circular region of radius R and centered at origin.

y = r sin

area element  ( dx dy ) = ( dr r d)

Hence integration becomes

Above integration vanishes because sine function is integrated from 0 to 2π .

Hence , we get

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Integration of cosine function over a range from 0 to 2π vanishes

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