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MHT CET202013 Oct 2020Morning ShiftMathematicsApplication of DerivativesActual

The radius of a circle is increasing at the rate 2 ~cm / sec . The rate at which its area is increasing when the radius of the circle is 5 decimeters is

Options

  1. A100 cm ² / sec
  2. B200 cm ² / sec
  3. C2000 cm ² / sec
  4. D20 cm ² / sec

Correct answer

B. 200 cm ² / sec

Step-by-step solution

Here dr dt =2 and r =5 decimeter =50 ~cm Now Area of circle = A = r ² . aligned d A dt &=2 r dr dt &=2 50 2=200 cm ² / sec aligned

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