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anonymous

  • 5 years ago

The radius of a circle is increasing. At a certain instant, the rate of increase in the area of the circle is numerically equal to twice the rate of increase in its circumference. What is the radius of the circle at that instant?

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  1. Yuki
    • 5 years ago
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    if you let x be your radius, you can find both the area and the circumference as a function of x. can you do that ?

  2. Yuki
    • 5 years ago
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    Now you want to know what "rate of increase in the area" and "rate of increase in the circumference" is algebraically.

  3. Yuki
    • 5 years ago
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    I'm just going to assume that you are reading this. if you let the Area of the circle "A" then the rate of increase of A would be A'. More precisely, dA/dt since we are focusing on how fast the area is changing regarding at what time

  4. Yuki
    • 5 years ago
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    similarly, if you let "C" be the circumference dC/dt would be the rate of increase at a certain time t where the unit is in meters/second.

  5. Yuki
    • 5 years ago
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    Do you understand so far ?

  6. dumbcow
    • 5 years ago
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    i think they left

  7. Yuki
    • 5 years ago
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    let me know if you still need help

  8. dumbcow
    • 5 years ago
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    oh well here is answer radiuis = 2

  9. anonymous
    • 5 years ago
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    Is there a formula that i need to use to solve this?

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