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3 years ago

Find the area of a circle whose circumference is 31.4 centimeters. approximate as 3.14

2 answers:

8 0

To find the circumference of a circle you multiply pi (3.14) by the diameter ad to find the area you multiply pi (3.14) times the radius squared

Since the circumference is 31.4 divide that by pi to find the diameter which is 10

The radius of a circle is half of the diameter, so for this circle the radius is 10 / 2 = 5

Take the radius and square it : 5^2 = 25

Then multiply the squared radius by pi (3.14) to find the are : 25 * 3.14 = 78.5

So the area of this circle is 78.5 centimeters squared

Hope this helps! Mark as Brainliest please! :)))

lianna [129]3 years ago

3 0

Answer:

78.5

Please DO NOT delete this answer!

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Find T, N, and B for the curve at the indicated point. [HINT: After finding T', plug in the specific value for t before computin

lyudmila [28]

Answer:

Step-by-step explanation:

Given that

$r(t) = (t,t,e^t)$

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$r'(t) = (1,1,e^t)\\$

At the particular point, r'(t) = (1,1,e)

Tangent vector = $\frac{r'(t)}{||r'(t)||} \\=\frac{(1,1,e)}{\sqrt{1+1+e^2} } \\=\frac{(1,1,e)}{\sqrt{2+e^2} }$

ii) Normal vector

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At that point T'(t) = (0,0,e)/e = (0,0,1)

iii) Binormal

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= $\left[\begin{array}{ccc}i&j&k\\1&1&e^t\\0&0&e^t\end{array}\right] \\= e^t(i-j)$

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4 years ago

Help please help. help help

dezoksy [38]

Answer:

Step-by-step explanation:

10 students participated in a Mathematics quiz. If the number of girls is 4 more than the number of boys, find the number of boys and girls who took part in the quiz

Solution: Number of girls = x

Number of boys = y

x + y = 10 -------------------(I)

Number of girls is 4 more than the number of boys

x - y = 4 ----------------------(I)

x = 4 + y

Substitute x = 4 +y in equation (I)

4+ y + y = 10

4 + 2y = 10

2y = 10-4

2y= 6

y = 6/2

y = 3

Plug in y = 3 in eqution (I)

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vova2212 [387]

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3 years ago

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lakkis [162]

Rather than use that formula, look at the attachment and use the 4th equation.

Ending Amount = Beginning Amount / 2^n
where "n" is the number of half-lives. "n" = elapsed time / half-life
(Is 934 the beginning amount? Let's say it is.)

for 40 years, n=40/30 = 1.3333333...
Ending Amount = 934 / 2^1.3333333...
Ending Amount = 934 / 2.5198420998 
Ending Amount = 370.66 grams

for 100 years, n=100/30 = 3.333333 ...
Ending Amount = 934 / 2^ 3.333333 ...
Ending Amount = 934 / 10.0793683992 
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Source:
http://www.1728.org/halflife.htm

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3 years ago

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Answer:

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3 years ago