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3 years ago

Given that f(x) = x² + 4x, evaluate f(-2). -4 -8 -12

Mathematics

2 answers:

Anna71 [15]3 years ago

8 0

f(-2) = (-2)^2 + 4(-2)
f(-2) = 4 - 8
f(-2) = -4

Dimas [21]3 years ago

7 0

Answer:

-4

Step-by-step explanation:

Given that f(x) = x² + 4x, evaluate f(-2).

-4

-8

-12

Odyssey

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A class survey in a large class for first-year college students asked, “About how many minutes do you study on a typical weeknig

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Answer: (110.22, 125.78)

Step-by-step explanation:

The confidence interval for the population mean is given by :-

$\mu\ \pm z_{\alpha/2}\times\dfrac{\sigma}{\sqrt{n}}$

Given : Sample size = 463

$\mu=118\text{ minutes}$

$\sigma=65\text{ minutes}$

Significance level : $\alpha=1-0.99=0.01$

Critical value : $z_{\alpha/2}=z_{0.005}=\pm2.576$

We assume that the population is normally distributed.

Now, the 90% confidence interval for the population mean will be :-

$118\ \pm\ 2.576\times\dfrac{65}{\sqrt{463}} \\\\\approx118\pm7.78=(118-7.78\ ,\ 118+7.78)=(110.22,\ 125.78)$

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3 years ago

Identify the expression that is equivalent to cot x/ csc x -1

Yuri [45]

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(cosx/sinx)(sinx) - 1

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3 years ago

Graph the function f(x) = -x-8x-13

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Answer:

the answer is there...

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3 years ago

Jennifer is saving money to buy a bike. The bike costs $246. She has $138 saved, and each week she adds $18 to her savings.

Brrunno [24]

Answer: 8 weeks

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3 years ago

A farmer has a basket of peaches. He gives ⅓ of the peaches to one person, ¼ to another, ⅕ to another, ⅛ to another, and then gi

inessss [21]

Answer:

$\frac{1429}{120}$ or $11\frac{109}{120}$

Step-by-step explanation:

Given:

A farmer has a basket of peaches. He gives ⅓ of the peaches to one person, ¼ to another, ⅕ to another, ⅛ to another, and then gives 7 peaches to a 5th person.

Remaining peaches = 4

We need to find the original number of peaches in the basket.

The farmer gives the total number of peaches = $\frac{1}{3}+\frac{1}{4}+\frac{1}{5}+\frac{1}{8}+7$

Let x be the former gives the total number of peaches

We multiply and divide by 120 in right side of the above equation because of 120 is divided by all given denominator and then simplify.

$x = \frac{120}{120}(\frac{1}{3}+\frac{1}{4}+\frac{1}{5}+\frac{1}{8}+7)$

$x = \frac{1}{120}(\frac{120}{3}+\frac{120}{4}+\frac{120}{5}+\frac{120}{8}+7\times 120)$

$x = \frac{1}{120}(40+30+24+15+840)$

$x = \frac{1}{120}(949)$

$x = \frac{949}{120}$

We add the remaining peaches by given peaches for the original number of peaches in the basket.

Original number of peaches = $\frac{949}{120}+4$

Original number of peaches = $\frac{949+4\times 120}{120}$

Original number of peaches = $\frac{949+480}{120}$

Original number of peaches = $\frac{1429}{120}$

Original number of peaches = $11\frac{109}{120}$

Therefore the original number of peaches in the basket is $\frac{1429}{120}$ or $11\frac{109}{120}$

5 0

3 years ago