Nhiệt độ tại điểm (x,y) trên một tấm kim loại phẳng được cho bởi T(x,y)=60/(1+x²+y²), trong đó T là nhiệt đo theo °C và x,y theo mét. Tìm tốc độ biến thiên nhiệt độ theo khoảng cách tại điểm (2,1) theo hướng -x và theo hướng -y.

Answer:

0.76

Step-by-step explanation:0.76

Answer:

37 / 16

Step-by-step explanation:

_____________________

Answer:

55

Step-by-step explanation:

u + xy, for u = 20, x = 5, and y = 7

u + xy = 20 + 5 * 7 = 20 + 35 = 55

Step-by-step explanation:

hear is your please check attachment

Answer:

The answer is "Approximately normal".

Step-by-step explanation:

sample size[tex]n=100[/tex]

Sample size [tex]n \geq 30[/tex]

It is because [tex]C \perp T[/tex] the sampling distribution of the sample means is approximately normal.

Answer:

in three different ways the first one gets a gold one the other 4 printers get silver n the last 4 printers get bronze.

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Answer:

  B.  16:49

Step-by-step explanation:

The area ratio is the square of the edge length ratio:

  area ratio = (4:7)² = 4²:7² = 16:49

_____

It might help you to recall that area is the product of two linear dimensions if each is multiplied by 4/7, the resulting product will be multiplied by (4/7)².

  A = LW

  A' = (4/7L)(4/7W) = (4/7)²(LW) = (16/49)·A

Step-by-step explanation:

Given that,

a. x = 15 and y = 14

The equation is :

x = ky

or

[tex]k=\dfrac{x}{y}[/tex]

Put all the values,

[tex]k=\dfrac{15}{14}\\\\k=1.07[/tex]

b. Now, put y = 70 and k = 1.07.

x = 1.07×70

x = 74.9

c.

Put x = 45 and k = 1.07.

[tex]y=\dfrac{x}{k}\\\\y=\dfrac{45}{1.07}\\\\y=42.05[/tex]

Hence, this is the required solution.

Answer:

i:

The appropriate null hypothesis is [tex]H_0: p \geq 0.2[/tex]

The appropriate alternative hypothesis is [tex]H_1: p < 0.2[/tex]

The p-value of the test is 0.1057 > 0.05, which means that there is not sufficient evidence that fewer than 20% of the museum visitors make use of the device, and so, it should not be withdrawn.

ii:

The p-value of the test is 0.1057

Step-by-step explanation:

Question i:

The device will be withdrawn if fewer than 20% of all of the museum’s visitors make use of it.

At the null hypothesis, we test if the proportion is of at least 20%, that is:

[tex]H_0: p \geq 0.2[/tex]

At the alternative hypothesis, we test if the proportion is less than 20%, that is:

[tex]H_1: p < 0.2[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

0.2 is tested at the null hypothesis:

This means that [tex]\mu = 0.2, \sigma = \sqrt{0.2*0.8} = \sqrt{0.16} = 0.4[/tex].

The device will be withdrawn if fewer than 20% of all of the museum’s visitors make use of it. Of a random sample of 100 visitors, 15 chose to use the device.

This means that [tex]n = 100, X = \frac{15}{100} = 0.15[/tex]

Test statistic:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

[tex]z = \frac{0.15 - 0.20}{\frac{0.4}{\sqrt{100}}}[/tex]

[tex]z = -1.25[/tex]

P-value of the test and decision:

The p-value of the test is the probability of finding a sample proportion below 0.15, which is the p-value of z = -1.25.

Looking at the z-table, z = -1.25 has a p-value of 0.1057.

The p-value of the test is 0.1057 > 0.05, which means that there is not sufficient evidence that fewer than 20% of the museum visitors make use of the device, and so, it should not be withdrawn.

Question ii:

The p-value of the test is 0.1057

Answer:

540

Step-by-step explanation:

720 (100-25) to find the decimal to use (below 1.00 is decreasing)

720 (.75) = 540

Answer:

The answer is "Option B".

Step-by-step explanation:

Please find the complete question in the attached file.

The Horizontal stretch [tex]=(\frac{1}{6 \ x})\\\\[/tex]

Translation by 5 units right[tex]=( \frac{1}{6\ x})-5[/tex]

Answer:

its A i used his answer and got it wrong

Answer:

You need to add the picture unless we cannot answer your question

Step-by-step explanation:

Please add the picture it would be very useful and essential to find the answer

Answer:

Add pictures plis

Step-by-step explanation:

Answer:

-3/9x

Step-by-step explanation:

You rearrange for 'y' so divide both sides by it's coefficient which is 9.

Answer:

The slope is -1/3

Answer:

D

Step-by-step explanation:

If you add or subtract three outside of the exponent (ex: x^2 + 3), then the parabola moves up and down.

If you add or subtract the number inside the exponent (ex: (x+3)^2), then the parabola moves side to side.

If you add three, the parabola moves left.

Thus, the answer is D.

[tex]\sf\purple{A.\:Between \:12\:and\:13.}[/tex] ✅

[tex]\large\mathfrak{{\pmb{\underline{\red{Step-by-step\:explanation}}{\orange{:}}}}}[/tex]

[tex] \sqrt{156} \\ = 12.4899 \\ = 12.49[/tex]

Therefore, [tex] \sqrt{156} [/tex] will fall in between 12 and 13.

[tex]\large\mathfrak{{\pmb{\underline{\orange{Happy\:learning }}{\orange{!}}}}}[/tex]

Step-by-step explanation:

a and b are corresponding angles

Answer:

8n+10

Step-by-step explanation:

gimmi brainiest answer or me no give cookie

Answer:

Step-by-step explanation:

A= (a + b) * h/2

Answer:

what they said

Step-by-step explanation:

yeah what they said

thx thx thx thx thx thx thx sa points sabi mo give away eh

I hope this is help full to you

Answer:

39,144,000 km

Step-by-step explanation:

Hi there!

Distance traveled = time * speed

Given speed: 233000 km/h

Given time: 7 days

It's important to note that our speed is given in per hours and out time is given in days. So in order to find how far the comet has traveled we must convert days to hours.

There are 24 hours in 1 day.

So to convert days to hours simply multiply amount of days by 24

24 * 7 = 168

So the comet has traveled for 168 hours

Now we can find distance traveled

Once again distance traveled = time * speed

Given speed is 233000 km/h

Given time is 168 hours

Distance = 168 * 233000 = 39,144,000

So the comet has traveled for a total distance of 39,144,000 km

Answer:

[tex]5800[/tex]

Step-by-step explanation:

Hope it is helpful...

Answer:

5800

Step-by-step explanation:

5763

7 is in the hundreds place

We look at the tens place to determine how to round

If the tens place is 5 or above we round up, if it is 4 or less- leave it alone

Since 6 is 5 or above, we round the 7 up

5763 rounds to 5800

Answer:

C ................................. I think

Answer: 11:45 am

Step-by-step explanation:

10:15

toget back down 10

;15          

Answer:

The correct option is (b).

Step-by-step explanation:

The solution of the given polynomial is :

[tex](-\dfrac{1}{3},4)[/tex]

x = 1/3 and y = -4

i.e.

Sum of roots = (1/3-4) = -11/3

Product of roots = (1/3)(-4) = -4/3

The quadratic equation is as follows :

[tex]x^2+(\text{sum of roots})x+\text{Product of roots}=0[/tex]

Put all the values,

[tex]x^2+\dfrac{-11}{3}x+\dfrac{-4}{3}=0\\\\3x^2-11x-4=0[/tex]

So, the correct option is (b).

Answer:

The selling price of the shoe is $18

Step-by-step explanation:

Hey there!

According to the question, the normal cost price of pair of shoes is $24 (i.e $24 is MP= marked price).

Also, there is 25% off. (i.e discount)

Now,

SP (selling price) = MP - discount% of MP

or, SP = 24 - 25% of 24

or, SP= 24 - 6

Therefore, the SP of the shoes is $18.

Hope it helps!

$18

The answer is $18

Answer:

C

Step-by-step explanation:

Using pythagoras theorem, you will find that AC= 12,

[tex]\sqrt{13^2-5^2}= 12[/tex]

Sin A = Opposite / Hypotenuse, in this case the opposite of A is CB which is 5ft, and then Hypotenuse of the right angled triangle is AB. which is 13ft.

So, Sin A = 5/13

Tan A= Opposite/ Adjacent,

Opposite is CB, which is 5ft, adjacent is AC, which  is 12ft.

So, Tan A= 5/12

Cos A= Adjacent/Hypotenuse,

we know adjacent is 12ft and that hypotenuse is 13ft.

So Cos A= 12/13

However Sec A is the inverse of cos A.

So, Sec A= 13/12.

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Answer:

  3x^2

Step-by-step explanation:

Add coefficients of like terms.

  (x^2 +2x -1) +(2x^2 -2x +1)

  = (1 +2)x^2 +(2 -2)x +(-1 +1)

  = 3x^2 +0x +0

  = 3x^2

Answer:

3x^2

Step-by-step explanation:

(x^2+2x−1)+(2x^2−2x+1)

Combine x^2 and 2x^2 to get 3x^2.

3x^2+2x−1−2x+1

Combine 2x and −2x to get 0.

3x ^2−1+1

Add −1 and 1 to get 0.

3x^2

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Answer:

  C is one half the area of a rectangle with sides 6 units * 2 units

Step-by-step explanation:

The area of any triangle is half the area of a rectangle of the same height and width. Here, the triangle has a width of 6 units and a height of 2 units. Its area is ...

  one half the area of a rectangle with sides 6 units by 2 units

2.5m = 75

To find m divide both sides by 2.5:

M = 75/2.5

M = 30

Answer:

m = 30

Step-by-step explanation:

2.5 m = 75

To find m divide 75 by 25

m = 75 / 2.5

m = 30