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2 years ago

Find the area of a circle with a circumference of 31.4 units. help me please

Mathematics

1 answer:

hram777 [196]2 years ago

4 0

Answer:

Area = 78.5

Step-by-step explanation:

31.4 = 2 x pi X r

r = 31.4/(2xpi) = 31.4(2 x 3.14) = 5

Area = pi x r^2 = 3.14 X 5^2 =3.14 x 25 = 78.5 units^2

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Write a doubles fact to find the sum 3+2

valentina_108 [34]

Answer:

5 or -5

Step-by-step explanation:

3+2=5

-1(3+2)=-5

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3 years ago

What is the surface area of this cuboid?<br> height: 5cm<br> length: 9cm<br> width: 4cm

bazaltina [42]

Answer:

180

Step-by-step explanation:

formulae=H×L×W so....5×9×4=180

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2 years ago

Help Pls! It's for my Math 4! Scalar Multiplication!

prohojiy [21]

Answer:

Concept: Physics Qualitative Analysis.

Scalar values are constant and compared to vector values they do not have a direction or magnitude or a gradient representation.

Lets get started by setting up the equation
They want us to find 3U-2V
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Now we plug in and solve!
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Now with the skills you gained solve the rest!!!

8 0

3 years ago

Read 2 more answers

Consider the sequence 3, -9, 27, -81, .. Find the 14th term of the sequence.

bagirrra123 [75]

Answer:

let 'a' be the first term, 'd' be the common difference between all the terms of the sequence

Step-by-step explanation:

therefore, a = 3,

and, d = -9 -3

= -12

hence the 14th term would be,

=> a + 13d

=> 3 + 13( -12 )

=> 3 - 156

=> - 153

5 0

3 years ago

Read 2 more answers

You stand a known distance from the base of the tree, measure the angle of elevation the top of the tree to be 15â—¦ , and then

gogolik [260]

Answer:

The maximum possible error of in measurement of the angle is $d\theta_1 =(14.36p)^o$

Step-by-step explanation:

From the question we are told that

The angle of elevation is $\theta_1 = 15 ^o = \frac{\pi}{12}$

The height of the tree is h

The distance from the base is D

h is mathematically represented as

$h = D tan \theta$ Note : this evaluated using SOHCAHTOA i,e

$tan\theta = \frac{h}{D}$

Generally for small angles the series approximation of $tan \theta \ is$

$tan \theta = \theta + \frac{\theta ^3 }{3}$

So given that $\theta = 15 \ which \ is \ small$

$h = D (\theta + \frac{\theta^3}{3} )$

$dh = D (1 + \theta^2) d\theta$

=> $\frac{dh}{h} = \frac{1 + \theta ^2}{\theta + \frac{\theta^3}{3} } d \theta$

Now from the question the relative error of height should be at most

$\pm p$ %

=> $\frac{dh}{h} = \pm p$

=> $\frac{1 + \theta ^2}{\theta + \frac{\theta^3}{3} } d \theta = \pm p$

=> $d\theta = \pm \frac{\theta + \frac{\theta^3}{3} }{1+ \theta ^2} * \ p$

So for $\theta_1$

$d\theta_1 = \pm \frac{\theta_1 + \frac{\theta^3_1 }{3} }{1+ \theta_1 ^2} * \ p$

substituting values

$d [\frac{\pi}{12} ] = \pm \frac{[\frac{\pi}{12} ] + \frac{[\frac{\pi}{12} ]^3 }{3} }{1+ [\frac{\pi}{12} ] ^2} * \ p$

=> $d\theta_1 = 0.25 p$

Converting to degree

$d\theta_1 = (0.25* 57.29) p$

$d\theta_1 =(14.36p)^o$

4 0

3 years ago