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3 years ago

WILL GET BRAILIEST FOR CORRECT ANSWER

Mathematics

1 answer:

Alex Ar [27]3 years ago

5 0

Answer:

x = ± $\sqrt{20}$

Step-by-step explanation:

Given

x² = 20 ( take the square root of both sides )

x = ± $\sqrt{20}$

which can be simplified to

x = ± 2 $\sqrt{5}$

[ ± means plus or minus ]

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A plane flying horizontally at an altitude of 1 mile and a speed of 510 mi/h passes directly over a radar station. Find the rate

sdas [7]

Answer:

442 miles

Step-by-step explanation:

Given

To properly solve this question, I illustrate some given parameters using attached image

From the image, apply Pythagoras theorem

$x^2 + 1^2 = y^2$

Differentiate w.r.t time (t)

$2x\frac{dx}{dt} + 0 = 2y\frac{dy}{dt}$

$2x\frac{dx}{dt} = 2y\frac{dy}{dt}$

Divide both sides by 2

$x\frac{dx}{dt} = y\frac{dy}{dt}$

From the question, we have that the plan travels are 510mi/h.

This implies that:

$\frac{dx}{dt} = 510mi/h$

So, we then calculate the value of x when the distance (y) is 2mi i.e.:

$y = 2mi$

Apply Pythagoras theorem

$x^2 + 1^2 = y^2$

$x^2 + 1^2 = 2^2$

$x^2 + 1 = 4$

$x^2 = 4-1$

$x^2 = 3$

$x = \sqrt 3$

So, the expression becomes:

$x\frac{dx}{dt} = y\frac{dy}{dt}$

$\sqrt 3 * 510 = 2* \frac{dy}{dt}$

$\frac{\sqrt 3 * 510}{2} = \frac{dy}{dt}$

$\sqrt 3 * 255 = \frac{dy}{dt}$

$\frac{dy}{dt} = 255\sqrt 3$

$\frac{dy}{dt} = 255 * 1.7321$

$\frac{dy}{dt} = 441.655$

$\frac{dy}{dt} = 442$

<em>Hence, the distance is 442 miles</em>

7 0

2 years ago

Assume that when adults with smartphones are randomly selected, 52% use them in meetings or classes. If 14 adult smartphone us

emmasim [6.3K]

The probability that fewer than 4 of then use their smart phones in meetings or classes is 0.00030243747.

Step-by-step explanation:

Fewer than 4 means ,less than 4 which is any number less than 4 and not including 4. This is 3, 2,1 and 0. So you find the probability that exactly 3 of then use their smart phone, exactly 2 of them use their smart phones, exactly 1 of them use his/her smart phone and none of them.

Given that 52% use smartphones in meetings and classes =0.52

Thus the remaining 48% do not use smartphones in meetings and classes=0.48

For C(14,3) you will have "14 chose 3", number of ways of choosing 3 out of 14'

=(0.52)³ *(0.48)⁹=0.00019018714

For C(14,2) you will have "14 chose 2", number of ways of choosing 2 out of 14

=(0.52)²*(0.48)¹²=0.00004044841

For C(14,1) you will have "14 chose 1", number of ways of choosing 1 out of 14

=(0.52)¹*(0.48)¹³=0.000037337

For C(14,0) you will have "14 chose 0", number of ways of choosing 0 out of 14

=(0.52)⁰*(0.48)¹⁴=1*0.00003446492=0.00003446492

The probability that fewer than 4 of them use their smartphones in meetings or classes will be

0.00019018714 +0.00004044841+0.000037337+ 0.00003446492=0.00030243747

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Binomial random variable https://brainly.in/question/10088120

Keywords : Probability, random variable, binomial distribution

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4 0

3 years ago

A pet pharmaceutical company releases a new treatment, claiming to control fleas in cats for an average of 60 days per dose.

seraphim [82]

Fjdjsjshdnsnssmemsdm

4 0

2 years ago

Suppose that f(x)=x^2 and g(x)=-1/4(x+7)^2. Which statement best compares the graph of g(x) with the graph of f(x)?

wolverine [178]

Answer:

Both of these graphs are quadratics. They both form a parabola opening up

Step-by-step explanation:

The only difference between g(x) and f(x) is that g(x) is moved to the left 7 unit and has a horizontal stretch of 1/4

5 0

3 years ago

(2,1),(-3,1) how do you solve this I’m looking for the slope I also have to show work

shutvik [7]

Answer: 0

Step-by-step explanation:

To find the slope, you would need to use the formula $m=\frac{y_2-y_1}{x_2-x_1}$ .

$m=\frac{1-1}{-3-2} =\frac{0}{-5} =0$

The slope is 0, meaning the line is horizontal.

7 0

3 years ago