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KCET2016MathematicsApplication of Derivatives

The rate of change of area of a circle with respect to its radius ( r=2 cms ) is

Options

  1. A( 04 )
  2. B( 2 )
  3. C( 12 )
  4. D( 4 )

Correct answer

D. ( 4 )

Step-by-step solution

We know that, area of circle is given by [ A= r² ] [ So, d A d r =2 r ] At ( r=2 ~cm ), we have ( ( d A d r )_ r=2 =4 )

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