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soty2013

Find the rate of change of the area of a circle per second with respect to its radius r when r = 5 cm.

  • one year ago
  • one year ago

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  1. soty2013
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    @ParthKohli

    • one year ago
  2. ParthKohli
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    Differentiate \(\pi r^2\) with respect to \(r\).

    • one year ago
  3. ParthKohli
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    When you find \(f'(r)\), find \(f'(5)\)

    • one year ago
  4. soty2013
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    Thanks

    • one year ago
  5. ParthKohli
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    The answer turns out to be the circumference.

    • one year ago
  6. BAdhi
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    Actually shouldn't it be like this, $$A=\pi r^2$$ Since rate of change is associated with 'time' differentiation with respect to 't'- time, $$\frac{dA}{dt}=\pi\frac{dr^2}{dt}=2\pi r\frac{dr}{dt}$$ rate of change in radius should be given

    • one year ago
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