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2 years ago

Need help with this problem.

Mathematics

1 answer:

tigry1 [53]2 years ago

5 0

Answer:

C) $-\frac{47}{49}$

Step-by-step explanation:

By the cos double angle formula, we know $\cos(2\theta)=2\cos^2\theta-1.$ Substituting $\cos \theta$ into the formula, we get

$\cos(2\theta)=2(-\frac{1}{7})^2-1\\~~~~~~~~~~=\frac{2}{49}-1\\~~~~~~~~~~=\boxed{-\frac{47}{49}}$ .

The answer is C.

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A species of beetles grows 32% every year. Suppose 100 beetles are released into a field. How many beetles will there be in 10 y

siniylev [52]

Given that a species of beetles grows 32% every year.

So growth rate is given by

r=32%= 0.32

Given that 100 beetles are released into a field.

So that means initial number of beetles P=100

Now we have to find about how many beetles will there be in 10 years.

To find that we need to setup growth formula which is given by

$A=P(1+r)^n$ where A is number of beetles at any year n.

Plug the given values into above formula we get:

$A=100(1+0.32)^n$

$A=100(1.32)^n$

now plug n=10 years

$A=100(1.32)^{10}=100(16.0597696605)=1605.97696605$

Hence answer is approx 1606 beetles will be there after 20 years.

Now we have to find about how many beetles will there be in 20 years.

To find that we plug n=20 years

$A=100(1.32)^{20}=100(257.916201549)=25791.6201549$

Hence answer is approx 25791 beetles will be there after 20 years.

Now we have to find time for 100000 beetles so plug A=100000

$A=100(1.32)^n$

$100000=100(1.32)^n$

$1000=(1.32)^n$

$log(1000)=n*log(1.32)$

$\frac{\log\left(10000\right)}{\log\left(1.32\right)}=n$

33.174666862=n

Hence answer is approx 33 years.

4 0

4 years ago

Read 2 more answers

If a 30-60-90 right triangle has a hypotenuse 6, what is the length of the short leg?

Anton [14]

Answer:

$\sqrt[3]{3}$

Step-by-step explanation:

use the Pythagoras Theorem

Since you have the hypotenuse (6"), just go backwards. 62 = 36 = a2 + b2.

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3 years ago

micah uses 2 bags of birdseed to fill up 4 bird feeders. how many bags wi'll he need to fill up 40 feeders?

Gre4nikov [31]

2 bags = 4 feeders
You need 40 feeders.
40 feeders (need to fill up) ÷ 4 (feeders per 2 bags) = 10
10 x 2 (bags) =
20 bags for 40 feeders

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4 years ago

Read 2 more answers

Select each expression that is equivalent to 3n+6 select all that apply. Explan.

arsen [322]

A, C. A is obviously correct because it’s the e same thing and C you combine like terms (2n+n=3n,2+4=6,=3n+6) it’s not B because it’s not 18, it’s not D because you’d get 3n+18 and it’s not E because you’d get 3n+12, meaning the only correct answers are A and C

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3 years ago

suppose you performed a regression analysis. you were given four observations of the target at [1.0, 1.5, 2.8, 3.7], and you pre

Arlecino [84]

Suppose you performed a regression analysis. The mse for this scenario is 0.105

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We are able to say that age and peak can be described through the usage of a linear regression version. because someone's peak will increase as age will increase, they have got a linear courting. Regression fashions are commonly used as statistical proof of claims regarding regular statistics.

"Regression" comes from "regress" which in turn comes from Latin "regresses" - to head returned (to something). In that feel, regression is the approach that permits "to head again" from messy, hard-to-interpret data, to a clearer and more significant version.

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The error sum of the square is given by

ESS = (y- )

ESS=0.21

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MSE = 0.105

Learn more about regression here brainly.com/question/26755306

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6 0

2 years ago

Need help with this problem. ​

Need help with this problem.