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Sholpan [36]
3 years ago
5

4. What is the circumference of a circle whose area is 81π cm squared?

Mathematics
2 answers:
vichka [17]3 years ago
7 0
Area = pi*r^2
Circumference = 2pi*r

Step 1: find the radius from area
81pi=pi*r^2
81=r^2
9=r

Step 2: plug in radius to the circumference equation

Circumference = 2pi*r

18pi is the answer, otherwise know as 56.52 as well.
pogonyaev3 years ago
3 0

Step-by-step explanation:

Let us assume R be the radius of circle We know that, area of circle = πR2 81πr2 = πR2 R = √81 r R = 9r Circumference = 2 πr = 2 π (9r) = 18πr

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On the basis of data collected during an experiment, a biologist found that the growth of a fruit fly population (Drosophila) wi
Ket [755]

Answer:

(a). 15

(b). 78

Step-by-step explanation:

Growth of the population of a fruit fly is modeled by

N(t) = \frac{600}{1+39e^{-0.16t} }

where t = number of days from the beginning of the experiment.

(a). For t = 0 [Initial population]

N(0) = \frac{600}{1+39e^{-0.16\times 0} }

       = \frac{600}{1+39}

       = \frac{600}{40}

       = 15

Initial population of the fruit flies were 15.

(b).Population of the fruit fly colony on 11th day.

N(11) = \frac{600}{1+39e^{-0.16\times 11} }

       = \frac{600}{1+39e^{-1.76} }

       = \frac{600}{1+39\times 0.172 }

       = \frac{600}{1+6.71}

       = \frac{600}{7.71}

       = 77.82

       ≈ 78

On 11th day number of fruit flies colony were 78.

3 0
3 years ago
René is twice as old as Jim In four years the sum of their ages is 60 how old are they now
Brrunno [24]
R=16
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zubka84 [21]
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Circles M and K are congruent and QR is congruent to LN. Find QR
ddd [48]

At first, we need to find x.

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Substitute value of a=8 into QR = 2x+1.

QR = 2*8+1 = 17

QR =17

5 0
3 years ago
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