Matrix A is said to be involutory if A2 = I. Prove that a square matrix A is both orthogonal and involutory if and only if A is symmetric.

Answer:

correct option is C)  2.8

Step-by-step explanation:

given data

string vibrates form =  8 loops

in water loop formed =  10 loops

solution

we consider  mass of stone = m

string length = l

frequency of tuning = f

volume = v

density of stone = [tex]\rho[/tex]

case (1)  

when 8 loop form with 2 adjacent node is [tex]\frac{\lambda }{2}[/tex]

so here

[tex]l = \frac{8 \lambda _1}{2}[/tex]      ..............1

[tex]l = 4 \lambda_1\\\\\lambda_1 = \frac{l}{4}[/tex]

and we know velocity is express as

velocity = frequency × wavelength   .....................2

[tex]\sqrt{\frac{Tension}{mass\ per\ unit \length }}[/tex]   =   f × [tex]\lambda_1[/tex]

here tension = mg

so

[tex]\sqrt{\frac{mg}{\mu}}[/tex]   =   f × [tex]\lambda_1[/tex]     ..........................3

and

case (2)  

when 8 loop form with 2 adjacent node is [tex]\frac{\lambda }{2}[/tex]

[tex]l = \frac{10 \lambda _1}{2}[/tex]      ..............4

[tex]l = 5 \lambda_1\\\\\lambda_1 = \frac{l}{5}[/tex]

when block is immersed

equilibrium  eq will be

Tenion + force of buoyancy = mg

T + v × [tex]\rho[/tex] × g = mg

and

T = v × [tex]\rho[/tex] - v × [tex]\rho[/tex] × g    

from equation 2

f × [tex]\lambda_2[/tex] = f  × [tex]\frac{1}{5}[/tex]  

[tex]\sqrt{\frac{v\rho _{stone} g - v\rho _{water} g}{\mu}} = f \times \frac{1}{5}[/tex]     .......................5

now we divide eq 5 by the eq 3

[tex]\sqrt{\frac{vg (\rho _{stone} - \rho _{water})}{\mu vg \times \rho _{stone}}} = \frac{fl}{5} \times \frac{4}{fl}[/tex]

solve irt we get

[tex]1 - \frac{\rho _{stone}}{\rho _{water}} = \frac{16}{25}[/tex]

so

relative density [tex]\frac{\rho _{stone}}{\rho _{water}} = \frac{25}{9}[/tex]

relative density = 2.78 ≈ 2.8

so correct option is C)  2.8

There are [tex]10[/tex] divisions between $3.2$ and $3.3$

so that means each division is $\frac{3.3-3.2}{10}=0.01$

A is the 3rd division after $3.2$, So A is $3.2+3\times0.01=3.23$

similarly, C is 3 division behind $3.2$ so it will be $3.17$

and B is $3.34$

A represents the decimal 3.23

B represents the decimal 3.34

C represents the decimal 3.17

We can see that there are 10 divisions between 3.2 and 3.3.

The difference between the two points for 10 divisions is 3.3 -3.2 = 0.1 unit.

Therefore, one division will be equal to 0.1/10 = 0.01 unit

So, point A is 3 divisions after 3.2, thus

A = 3.2 + 0.01×3

A = 3.23

Similarly,

B = 3.3 + 0.01×4

B = 3.34

And,

C = 3.2 - 0.01×3

C = 3.17

Learn more about decimals:

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Answer:

-4.5ft per sec

Step-by-step explanation:

Assume that vertical wall has a distance of y and the horizontal floor is x (6 ft).

This forms a triangle with the ladder as the hypothenus of length 10ft

We have dy/dt = 6ft per sec

According to Pythagoras law the relationship between x and y is

(x^2) + (y^2) = (hypothenus ^2) = 10^2

When we differentiate both sides of the equation

2x(dx/dt) + 2y(dy/dt) = 0

dy/dt = (x/y) * (dx/dt)

y= √(10^2) - (6^2) = 8ft

So dy/dt = (6/8)* (6/1)= -4.5 ft per sec

It is a negative rate

Answer:

A. The stepwise selection procedure uses Adjusted R-square as the "best" model criterion.

Step-by-step explanation:

Stepwise regression is a model which uses variables in step by step manner. The procedure involves removal or inclusion of independent variables one by one. It adds the most significant independent variable and removes the less significant independent variable. Usually stepwise selection uses R-square or Mallows Cp for picking the best fit.

Answer: First a horizontal shift of 8 units, then a reflection over the x-axis, and then a vertical shift of 20 units.

Step-by-step explanation:

Let's construct g(x) in baby steps.

Ok, we start with f(x) = x^2

The first thing we have is a horizontal translation of A units (where A is not known)

A vertical translation of N units to the right, is written as:

g(x) = f(x - N)

Then we have:

g(x) = (x - A)^2 = x^2 - 2*A*x + A^2

Now, you can see that actually g(x) has a negative leading coefficient, which means that we also have an inversion over the x-axis.

Remember that if we have a point (x, y), a reflection over the x-axis transforms our point into (x, -y)

Then if we apply also a reflection over the x-axis, we have:

g(x) = -f(x - A) = -x^2 + 2*A*x - A^2 = -x^2 + 16*x - 44

Then:

2*A = 16

A*A = 44.

The first equation says that A = 16/2 = 8

But 8^2 is not equal to 44.

Then we need another constant coefficient, which is related to a vertical translation.

If we have a relation y = f(x), a vertical translation of N units up, will be

y = f(x) + N.

Then:

g(x) = -f(x - A) + B

-x^2 + 2*A*x - A^2 + B = x^2 + 16*x - 44

Now we have:

2*A = 16

-A^2 + B = - 44

From the first equation we have A = 8, now we replace it in the second equation and get:

-8^2 + B = -44

B = -44 + 64 = 20

Then we have:

The transformation is:

First an horizontal shift of 8 units, then a reflection over the x-axis, and then a vertical shift of 20 units.

Answer:

3/4

Step-by-step explanation:

find a common number that 18 and 24 are both divisible by. I chose 6. So when i divide 6 by 18, I got 3. Which I put on my numerator, when I divided 24 by 6 I got 4 which I put on my denominator. My end result was 3/4

Answer:

3/4

Step-by-step explanation:

18/24

=2*9=18

=2*12=24

=9/12

=3/4

Answer: A) 0

P(A and B) = 0 when events A and B are disjoint, aka mutually exclusive.

We say that two events are mutually exclusive if they cannot happen at the same time. An example would be flipping a coin to have it land on heads and tails at the same time.

the answer is 667.

100/x = 15/100

it’s a proportion so you cross multiply. after cross multiplying you get 15x = 10,000. divided both sides by 15 and you get x = 66.6 (continuation of the 6). since it’s repeating, round it and you get 667.

by the way this is actually one of my homework questions for today ;)

The predicted number of butterflies that starts from Kansas and Missouri and migrate to Mexico is 667.

The Aim of the experiment is to measure the Monarch butterfly migration

Predicting the number of butterflies

= [tex]\frac{100}{x} = \frac{15}{100}[/tex]

= [tex]15x = ( 100 * 100)[/tex]

∴ x( predicted value ) = [tex]\frac{10000}{15 } = 667[/tex]

hence the approximate value of the number of butterflies that migrate to Mexico from Kansas and Missouri is  667

learn more about migration : https://brainly.com/question/23903333

Answer:

a) 6.00

b) 3.00

c) 1.50

Step-by-step explanation:

Sample error of the mean is expressed mathematically using the formula;

SE = σ /√n where;

σ  is the standard deviation and n is the sample size.

a) Given σ = 18, n = 9

Standard error of the mean = σ /√n

Standard error of the mean = 18/√9

Standard error of the mean = 18/3

Standard error of the mean = 6.00

b) Given σ = 18, n = 36

Standard error of the mean = σ /√n

Standard error of the mean = 18/√36

Standard error of the mean = 18/6

Standard error of the mean = 3.00

c) Given σ = 18, n = 144

Standard error of the mean = σ /√n

Standard error of the mean = 18/√144

Standard error of the mean = 18/12

Standard error of the mean = 3/2

Standard error of the mean = 1.50

Answer:

[tex]\boxed{\sf x = 80}[/tex]

Step-by-step explanation:

A quadrilateral inscribed in a circle has opposite sides equal to 180.

So,

x + x + 20 = 180

2x + 20 = 180

Subtracting 20 from both sides

2x = 180 - 20

2x = 160

Dividing both sides by 2

x = 80

━━━━━━━☆☆━━━━━━━

▹ Answer

x = 80

▹ Step-by-Step Explanation

x + x + 20 = 180

2x + 20 = 180

2x = 180 - 20

2x = 160

x = 80

Hope this helps!

CloutAnswers ❁

Brainliest is greatly appreciated!

━━━━━━━☆☆━━━━━━━

Answer:

The price for 4 people is 52 dollars.

4 × (5.75 + 7.25) = 52

The total cost including drink and popcorn is $52 according to a given condition.

Determine the known quantities and designate the unknown quantity as a variable while trying to set up or construct a linear equation to fit a real-world application.

In other words, an equation is a set of variables that are constrained through a situation or case.

Cost of movie ticket =  $7.25/person

Cost of popcorn and drink =  $5.75/person

Total cost per person = 5.75 + 7.25 = $13

Now,

Number of people = 4

So,

4(5.75 + 7.25) = 4(13) = $52

Hence "The total cost including drink and popcorn is $52 according to a given condition".

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Answer:

distance from the flying object to

the ground

= 7.2 melo(unit of measurement)

Step-by-step explanation:

The distance between the robot and Jo is 5 melo( unit Of measurement)

Let the distance between the flying object and the ground= y

Let's the remaining length of the closest between robot and Jonny and the ground be x.

Y/(x+5)= tan 29.... equation 1

Y/x= tan 42.... equation 2

Equating the value of y

Tan 29(x+5) = tan42(x)

Tan29/tan 42 = x/(x+5)

0.61562(x+5)= x

3.0781= x- 0.61562x

3.0781= 0.38438x

3.0781/0.38438= x

8.008= x

8= x

Y/x= tan 42

Y/8= 0.9004

Y= 7.203

Y= 7.2 melo (unit of measurement )

Answer:

finding the value of x first

2x + 3x + 10 = 180 (linear pair)

5x = 180 - 10

x = 170 / 5

x = 34

3x = 102

Answer:

3^x( 2-3^x)

Step-by-step explanation:

f(x) = 3^x and g(x) = 3^2x - 3^x

h(x) = f(x) - g(x)

       3^x - ( 3^2x - 3^x)

Distribute the minus sign

         3^x - 3^2x + 3^x

     2 * 3^x - 3 ^ 2x

Rewriting

We know that 3^2x = 3^x * 3^x

2 * 3^x - 3^x* 3^x

Factoring out 3^x

3^x( 2-3^x)

Answer:

you could stand at 5.0 ft and still be completely in the shadow of the tree

Step-by-step explanation:

From the diagram attached below;

We consider;

[tex]\overline {BC}[/tex] to be the height of the tree and [tex]\overline {DE}[/tex] to be the height of how tall you could be and still be completely in the shadow of the tree.

∠D = ∠B = 90°

Also;

ΔEAD = ΔBAC   (similar triangles)

Therefore, their sides will also be proportional

i.e

[tex]\dfrac{\overline {DE}}{ \overline {BC}}= \dfrac{\overline{AD}}{ \overline{AC}}[/tex]

[tex]\dfrac{x}{ 45}= \dfrac{225-220}{225}[/tex]

[tex]\dfrac{x}{ 45}= \dfrac{25}{225}[/tex]

By cross multiply

225x = 45 × 25

[tex]x = \dfrac{45 \times 25}{225}[/tex]

[tex]x = \dfrac{1125}{225}[/tex]

x = 5.0 ft

Therefore, you could stand at 5.0 ft and still be completely in the shadow of the tree

Answer:

13.75 dollars

Step-by-step explanation:

n=4

3n+7/n =3(4) + 7/4

=12 + 1.75

=$13.75

Answer: A) 4.75

Step-by-step explanation:

Answer:

x = 108

Step-by-step explanation:

The sum of a circle is 360

90 + x/2 + x+x = 360

Combine like terms

90 + 2x+x/2 = 360

90 + 5/2 x = 360

Subtract 90 from each side

5/2x = 270

Multiply each side by 2/5

5/2x * 2/5 = 270*2/5

x =108

Answer:

Step-by-step explanation:

Hello, please consider the following.

m and n are the two numbers.

m + n = 24, right?

n = 2 m

We replace n in the first equation, it comes

m + 2m =24

3m = 24 = 3*8

So, m = 8 and n = 16

Thank you

The first number is 8 and second number is 16.

Equation is the defined as mathematical statements that have a minimum of two terms containing variables or numbers is equal.

Arithmetic operations can also be specified by the subtract, divide, and multiply built-in functions.

Given that the sum of two numbers is twenty-four

The second number is equal to twice the first number

Let x and y are the two numbers.

According to the question,

m + n = 24,

n = 2m

Substitute the value of n in the first equation,

m + 2m =24

3m = 24

m = 24/3

m = 8

Substitute the value of m in the n = 2m

So, n = 2(8)

n = 16

Hence, the first number is 8 and second number is 16.

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Answer:

From the given points above, the distance between them is 4 units.

Step-by-step explanation:

In order to find the distance between the two points, we must know the distance formula.

[tex]d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]

Now, we plug in our numbers from the coordinate points that we are given to their respectful places.

[tex]d=\sqrt{(8-8)^2+(8-4)^2}[/tex]

Now, we solve. First, simplify the terms in parentheses. So, subtract 8 from 8 and subtract 4 from 8.

[tex]d=\sqrt{(0)^2+(4)^2}[/tex]

Next, solve for the exponents.

[tex]d=\sqrt{0+16}[/tex]

Add the numbers in the radical.  

[tex]d=\sqrt{16}[/tex]

Solve the radical.

[tex]d=4[/tex]

So, the distance  between the two given points is 4 units.

Answer:

The Confidence Interval = (0.172, 0.228)

Where:

The lower limit = 0.172

The upper limit = 0.228

Step-by-step explanation:

The formula to be applied or used to solve this question is :

Confidence Interval formula for proportion.

The formula is given as :

p ± z × √[p(1 - p)/n]

n = Total number of red candies = 550 red candles

p = proportion = Number of red candies counted/ Total number of red candies

= 110/550 = 1/5 = 0.2

z = z score for the given confidence interval.

We are given a confidence interval of 90%. Therefore, the z score = 1.6449

Confidence Interval = p ± z × √[p(1 - p)/n]

Confidence Interval = 0.2 ± 1.6449 × √[0.2(1 - 0.2)/550]

= 0.2 ± 1.6449 √0.2 × 0.8/550

= 0.2 ± 1.6449 × 0.0170560573

= 0.2 ± 0.0280555087

Hence, the Confidence Interval = 0.2 ± 0.0280555087

0.2 - 0.0280555087 = 0.1719444913

Approximately = 0.172

0.2 + 0.0280555087 = 0.2280555087

Approximately = 0.228

Therefore, the Confidence Interval = (0.172, 0.228)

Where:

The lower limit = 0.172

The upper limit = 0.228

Answer:

Lower Limit: 0.172

Upper Limit: 0.228

Step-by-step explanation:

Answer:

0.0319

Step-by-step explanation:

To approximate this probability, we shall be using the Bernoulli approximation of the Binomial distribution.

Let p = probability of selecting a reference book = 65% = 0.65

Let q = probability of selecting other books= 1-p = 1-0.65 = 0.35

Now, we want to find the probability that all of these 8 books to be re-shelved are reference book.

We set up the probability as follows;

P(X = 8) = 8C8 •p^8•q^0

P(X = 8) = 1 * (0.65)^8 * (0.35)^0

P(X = 8) = 0.031864481289 which is 0.0319 to 4 decimal places

Answer:

8 (19) or  8 (18 +1)

Step-by-step explanation:

Distributive property means to distribute.

HCF of 144 and 8.

=> 8 is the HCF of 144 and 8

8 (18 + 1)

=> 8 (19)

Answer:

396 in^2

Step-by-step explanation:

The perimeter of a triangle is given by the formula:

● P = 2w+2L

L is the length and w is the width

■■■■■■■■■■■■■■■■■■■■■■■■■■

The width hereis 18 inches and the perimeter is 80 inches.

Replace w by 18 and P by 80 to find L.

● P= 2L+2w

● 80 = 2L + 2×18

● 80 = 2L + 36

Substrat 36 from both sides

● 80-36 = 2L+36-36

●44 = 2L

Divide both sides by 2

● 44/2 = 2L/2

● 22 = L

So the length is 22 inches

■■■■■■■■■■■■■■■■■■■■■■■■■■

The area of a rectangle is given by the formula:

● A= L×w

● A = 22×18

● A = 396 in^2

Answer:

their difference in elevations are: they both don't fly one fly and one dive if you take the airplane it works quicker but if you take the submarine you won't reach faster

Answer:

50%

Step-by-step explanation:

22 is half of 44.

So, this means 50% of 44 is 22.

Answer:

$325.28

Step-by-step explanation:

152+152=304

304x1.07=325.28

Answer:

325.28

Step-by-step explanation:

increase the price by 100 %

152* 100%

152

Add this to the original price

152+152 = 304

Now find the sales tax

304 * 7%

304 * .07

21.28

Add this to the amount of the purchase price

304+21.28

325.28

Answer:

Following are the answer to this question:

Step-by-step explanation:

In the given statement, we don't agree with Ed’s conclusion, because it is not relevant simply since it is not statistically significant. The reduction of prostate cancer is the death risk, which is highly significant even if it decreases significantly. It can also be something statistically important without becoming important.

Answer:

219.80 feet

Step-by-step explanation:

Tan 20= 80/b

Tan 20= 0.363970234266

(0.363970234266)b=80

b= 219.80 feet

The distance between the sculpture and the bottom of the building is required.

The distance between the building and sculpture is 219.80 feet.

[tex]\theta[/tex] = Angle of depression = Angle of elevation = [tex]20^{\circ}[/tex]

p = Height of building = 80 feet

b = Required length

From the trigonometric ratios we have

[tex]\tan\theta=\dfrac{p}{b}\\\Rightarrow b=\dfrac{p}{\tan\theta}\\\Rightarrow b=\dfrac{80}{\tan 20}\\\Rightarrow b=219.80\ \text{feet}[/tex]

Learn more about trigonometry:

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Answer:

72 58 62 38 44 66 42 49 76 52 ( arrange it!)

38 42 44 49 52 58 62 66 72 76 (done!)

Median: Find the number in the middle after we arranged, so the answer is (52+58)/2= 110/2 = 55

Mode : None (there is no number appear more than other number)

Mean = (38+42+44+49+52+58+62+66+72+76)/10

=559/100

=5,5

Hope it helps ^°^

Answer:

[tex]\Huge \boxed{x=44}[/tex]

Step-by-step explanation:

The circumscribed angle and the central angle are supplementary.

∠ACB and ∠AOB add up to 180 degrees.

Create an equation to solve for x.

[tex]3x+10+38=180[/tex]

Add the numbers on the left side of the equation.

[tex]3x+48=180[/tex]

Subtract 48 from both sides of the equation.

[tex]3x=132[/tex]

Divide both sides of the equation by 3.

[tex]x=44[/tex]

Answer:

4)44

Step-by-step explanation: