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:

45° or 135°

Step-by-step explanation:

Cos 2x = 0

2x = cos^-1 0

2x = 90° or 270°

x= 45° or 135°

Answer:

Step-by-step explanation:

● cos 2x = 0

We khow that Pi/2 equals 0.

So

● 2x = Pi/2 or 2x= -Pi/2

Then:

● x = Pi/4 or x = -Pi/2

So the solutions are:

● x = Pi/4 + 2×k×Pi

● or x = -Pi/4 + 2×k×Pi

Where k is an integer

The picture below has a graphical solution

● Pi/4 is approximatively 0.785 and -Pi/4 is approximatively -0.785

● the output of both Pi/4 and -Pi/4 is 0

So our answer was righr

Answer:

Well this is my opinion I would try to compared both them and see if they have something familiar in their arguments. If not I would try to view their different point of view and write your own opinion about it. I would check out another book about the World War 2 because there's infinite of books about it.

Answer:

dddddd okaksy ogvurn

Step-by-step explanation:

d

Answer:

25.0000 + -37.5000 + 66.6667 + -63.5416 + 66.6667

Step-by-step explanation:

The actual formatting of the question has been attached to this response.

From the question,

Let the sequence of terms be [tex]b_{n}[/tex] i.e

[tex]b_{n}[/tex] = [tex]\frac{(-5)^{n+1} }{n!}[/tex]

Let the sequence of partial sums be [tex]S_{n}[/tex] i.e

[tex]S_{n}[/tex] = s₁ + s₂ + s₃ + . . . + sₙ

Therefore the first five terms of the sequence of partial sums will be S₅ i.e

S₅ =  s₁ + s₂ + s₃ + s₄ + s₅

Where;

s₁ = b₁

s₂ = b₁ + b₂ = s₁ + b₂

s₃ = b₁ + b₂ + b₃ = s₂ + b₃

s₄ = b₁ + b₂ + b₃ + b₄ = s₃ + b₄

s₅ = b₁ + b₂ + b₃ + b₄ + b₅ = s₄ + b₅

Where;

b₁ can be found by substituting n = 1 into equation (i) as follows;

[tex]b_{1}[/tex] = [tex]\frac{(-5)^{1+1} }{1!}[/tex]

[tex]b_{1}[/tex] = 25

[tex]b_{1}[/tex] = 25.0000

Recall that

s₁ = b₁

∴ s₁ = 25.0000 to 4 decimal places

--------------------------------------------------------------------------

b₂ can be found by substituting n = 2 into equation (i) as follows;

[tex]b_{2}[/tex] = [tex]\frac{(-5)^{2+1} }{2!}[/tex]

[tex]b_{2}[/tex] = -62.5

[tex]b_{2}[/tex] = -62.5000

Recall that

s₂ = s₁ + b₂

∴ s₂ = 25.000 + -62.5000 = -37.5000

-----------------------------------------------------------------------------------------

b₃ can be found by substituting n = 3 into equation (i) as follows;

[tex]b_{3}[/tex] = [tex]\frac{(-5)^{3+1} }{3!}[/tex]

[tex]b_{3}[/tex] = 104.1667

Recall that

s₃ = s₂ + b₃

∴ s₃ = -37.5000 + 104.1667 = 66.6667

--------------------------------------------------------------------------------

b₄ can be found by substituting n = 4 into equation (i) as follows;

[tex]b_{4}[/tex] = [tex]\frac{(-5)^{4+1} }{4!}[/tex]

[tex]b_{4}[/tex] = -130.2083

Recall that

s₄ =  s₃ + b₄

∴ s₄ = 66.6667 + -130.2083 = -63.5416

-------------------------------------------------------------------------

b₅ can be found by substituting n = 5 into equation (i) as follows;

[tex]b_{5}[/tex] = [tex]\frac{(-5)^{5+1} }{5!}[/tex]

[tex]b_{5}[/tex] = 130.2083

Recall that

s₅ = s₄ + b₅

∴ s₅ = -63.5416 + 130.2083 = 66.6667

------------------------------------------------------------------------------

Therefore, the first five terms of the partial sum is:

25.0000 + -37.5000 + 66.6667 + -63.5416 + 66.6667

Answer:

Hello your question is incomplete attached is the missing part the second curve ; y = 3x is incomplete so i would solve the problem taking the second curve as ; y = 3x + 8 ( giving you the general methodology )

answer : y = ( 5,32) , x = ( -1,8 )

area of shaded region = 90.673

Step-by-step explanation:

The given curves ; [tex]y = x^2 - 4x\\y = 3x +8[/tex]

solving the above curves simultaneously

[tex]x^2-4x = 3x + 8[/tex]

x^2 - 7x - 8 = 0

( x + 1 )(x - 8 ) = 0

hence  X = ( -1 , 8 )

Therefore y = 3x + 8

when x = -1 ,  y = -3 + 8 = 5

when x = 8 ,  y = 24 + 8 = 32

hence y = ( 5, 32 )

attached below is the sketched region

Integrating the curves to determine the shaded area in respect to x = ( -1, 8)

∫ [( 3x +8 ) - ( x^2 - 4x ) ] dx

∫ ( -x^2 +7x + 8 ) dx

= { - x^3/3  + 3x^2 + 8x }

= { - 8^3/3 + 3(64) + 64} - { -1^3/3 + 3 - 8 }

= {-170.66 + 192 + 64 } - { -1/3 - 5 }

= -170.66 + 192 + 64 + 5.333 = 90.673 ( area of the shaded region )

Answer:

10 units²

Step-by-step explanation:

Consider the unshaded region to consists of 2 triangles, ∆AED and ∆BEC, which are both of equal dimensions. Their bases and heights are both the same. Both triangles are embedded inside a rectangle ABCD.

Area of the shaded region = Area of rectangle - area of the 2 triangles.

Area of rectangle = l*w

l = 10

w = 2

[tex] Area_R = 10*2 = 20 units^2 [/tex]

Area of the 2 triangles = 2(½*b*h)

b = 2

h = 5

[tex]Area_T = 2(\frac{1}{2}*2*5)[/tex]

[tex] Area_T = 1*2*5 = 10 units^2 [/tex]

Area of shaded region = 20 - 10 = 10 units²

Answer:

I would say 70%

Step-by-step explanation:

He got 7 of of 10 (7/10 = 70%) right so I  would say he would do just as well without ESP since it doesn't exist.

Answer:

P = 3x - 4

Step-by-step explanation:

Side 1 = x - 3

Side 2 = x

Side 3 = 2 + (Side 1) = 2 + x - 3 = x - 1

Perimeter = 20 in

Perimeter = Side 1 + Side 2 + Side 3

Perimeter = (x - 3) + (x) + (x - 1)

Perimeter = x - 3 + x + x - 1

Perimeter = 3x - 3 - 1

Perimeter = 3x - 3 - 1

Perimeter = 3x - 4

P = 3x - 4

Answer:

The y-axis is upside down, meaning that instead of the values increasing as they go up, they decrease.

Answer: $ 11,232.00

Step-by-step explanation:

Given:  Amount = $ 10,800

Interest Rate = 8%   =0.08

Time in Months= 6.00

Formula :

Interest on Note = (Amount)× (Interest Rate) × ((Time in Months) /12)

= (10800)× (0.08)× (6/12)

= $432

The amount of the borrower's check =(Amount + Interest on Note)

= $ (10,800+432)

= $ 11,232.00

Hence, The amount of the borrower's check = $ 11,232.00

Answer:

2 chairs will be left over.

Step-by-step explanation:

Given that

There are a total of 1492 chairs.

which are to divided in 10 rows evenly.

To find:

Number of chairs left ?

Solution:

Let the number of chairs in each row = [tex]x[/tex]

There are 10 rows so number of chairs in rows = 10[tex]x[/tex]

Let the number of chairs left = [tex]y[/tex]

Total number of chairs =10[tex]x[/tex] + [tex]y[/tex]  = 1492

The above equation is like:

Divisor [tex]\times[/tex] Quotient + Remainder = Dividend

So, we have to find the remainder in this question where we are given Divisor and Dividend.

10 [tex]\times[/tex] 149 + 2 = 1492

So, dividing 1492 with 10, we get remainder as 2.

Hence, 2 chairs will be left.

Answer:

A. The interquartile range (IQR) for brand A, $10, is less than the IQR for brand B, $25.

Step-by-step explanation:

The most appropriate measure that can be used to compare the SPREAD of the data of the 2 brands plotted on a box plot, is the Interquartile range (IQR).

Interquartile range is the difference between Q3 and Q1.

Q3 is the value which lies at the end of the rectangular box, while the Q1 lies at the beginning of the box.

From the box plot given,

IQR for brand A = 80 - 70 = $10

IQR for brand B = 50 - 25 = $25

Therefore, the correct option is "A. The interquartile range (IQR) for brand A, $10, is less than the IQR for brand B, $25."

Answer:

4b + .60a

Step-by-step explanation:

b represents the number of bunches of bananas

a represents the number of apple

Multiply the cost by the number purchased of each item and add them together

4b + .60a

Answer:

[tex]\huge\boxed{\$ (4 b + 0.60 a)}[/tex]

Step-by-step explanation:

Bananas represented by b

1 banana costs $4 so b bananas will cost $ 4 b

Apples represented  by a

1 apples costs 0.60 $ so a apples will cost $ 0.60 a

Totally, they will cost:

=> $ (4 b + 0.60 a)

Answer:

Solution : ( - 8, - 5π/3 )

Step-by-step explanation:

There are four cases to consider here, the first two with respect to r > 0, the second two with respect to r < 0. For r < 0 we have the coordinates ( - 8, 60° ) and ( - 8, - 300° ) . - 300° in radians is - 5π/3, and hence our solution is option d. But let me expand on how to receive the coordinates. Again r is the directed distance from the pole, and theta is the directed angle from the positive x - axis.

So when r is either negative or positive, we can tell that this point is 8 units from the pole. Therefore - r = - 8 in both our second cases ( we are skipping the first two cases for simplicity ). For r < 0 the point will lay on the ray pointing in the opposite direction of the terminal side of theta.

Our first coordinate is ( - 8, 60° ). Theta will be 2 / 3rd of 90 degrees, or 60 degrees, for - r. Respectively the remaining degrees will be negative, 360 - 60 = 300, - 300. Our second point for - r will thus be ( - 8, - 300° ) . - 300° = - 5π/3 radians, and our coordinate will be ( - 8, - 5π/3 ).

Answer:

False

Step-by-step explanation:

The 98% is confidence interval its not a probability estimate. The probability will be different from the confidence interval. Confidence interval is about the population mean and is not calculated based on sample mean. Every confidence interval contains the sample mean. There is 98% confidence that the proportion of Drosophola with his mutation is between 0.34 and 0.38.

Answer:

Step-by-step explanation:

Given the equation solved by savanah expressed as [tex]3+4|\frac{x}{2} + 3| = 11[/tex], IF she solved for one of the solution and got x = -2, we are to solve for the other value of x.

Note that the expression in modulus can be expressed as a positive expression and negative expression.

For the positive value of the expression [tex]|\frac{x}{2} + 3|[/tex] i.e [tex]\frac{x}{2} + 3[/tex], the expression becomes;

[tex]3+4(\frac{x}{2} + 3) = 11[/tex]

On simplification;

[tex]3+4(\frac{x}{2} + 3) = 11\\\\3 + 4(\frac{x}{2} )+4(3) = 11\\\\3 + \frac{4x}{2}+ 12 = 11\\\\3 + 2x+12 = 11\\\\2x+15 = 11\\\\Subtract \ 15 \ from \ both \ sides\\\\2x+15-15 = 11-15\\\\2x = -4\\\\x = -2[/tex]

For the negative value of the expression [tex]|\frac{x}{2} + 3|[/tex] i.e [tex]-(\frac{x}{2} + 3)[/tex], the expression becomes;

[tex]3+4[-(\frac{x}{2} + 3)] = 11[/tex]

On simplifying;

[tex]3+4[-(\frac{x}{2} + 3)] = 11\\\\3+4(-\frac{x}{2} - 3)= 11\\\\3-4(\frac{x}{2}) -12 = 11\\\\3 - \frac{4x}{2} - 12 = 11\\\\3 - 2x-12 = 11\\\\-2x-9 = 11\\\\add \ 9 \ to \ both \ sides\\\\-2x-9+9 = 11+9\\-2x = 20\\\\x = -20/2\\\\x = -10[/tex]

Hence her other solution of x is -10

Answer:

The desired sample size is 97.

Step-by-step explanation:

Assume that 50% people in the community that supports the political candidate.

It is provided that the candidate wants a 10% margin of error (MOE) at a 95% confidence level.

The confidence interval for the population proportion is:

[tex]CI=\hat p\pm z_{\alpha/2}\sqrt{\frac{\hat p(1-\hat p)}{n}}[/tex]

Then the margin of error is:

[tex]MOE= z_{\alpha/2}\sqrt{\frac{\hat p(1-\hat p)}{n}}[/tex]

Compute the critical value of z as follows:

[tex]z_{\alpha/2}=z_{0.05/2}=z_{0.025}=1.96[/tex]

*Use a z-table.

Compute the sample size as follows:

[tex]MOE= z_{\alpha/2}\sqrt{\frac{\hat p(1-\hat p)}{n}}[/tex]

       [tex]n=[\frac{z_{\alpha/2}\times \sqrt{\hat p(1-\hat p)} }{MOE}]^{2}[/tex]

          [tex]=[\frac{1.96\times \sqrt{0.50(1-0.50)} }{0.10}^{2}\\\\=[9.8]^{2}\\\\=96.04\\\\\approx 97[/tex]

Thus, the desired sample size is 97.

Answer: Negative sign

Adding two negative values results in another negative value.

-1.69 + (-1.69) = -3.38

It's like starting $1.69 in debt and then adding 1.69 dollars of more debt. You'll slide further into debt being $3.38 in debt total.

The sign is negative as the value of -1.69 + (-1.69) is -3.38.

An expression is a way of writing a statement with more than two variables or numbers with operations such as addition, subtraction, multiplication, and division.

Example: 2 + 3x + 4y = 7 is an expression.

We have,

-1.69 + (-1.69)

= -1.69 - 1.69

= -3.38

This means,

The sign is negative.

Thus,

The value of -1.69 + (-1.69) is -3.38.

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Answer:

(-3,-3)

B=(6-9,6+3)

Answer:

114 km

Step-by-step explanation:

Each side is an isosceles trapezoid, so ED=2 since you would need to add 2 to each end of the bottom line to get the top line. Now use Pythagorean Theorem to get ED^2+AD^2=AE^2. Plug in your numbers to solve for AE. This is the height of each trapezoid. Then use your formula for the area of a trapezoid, (B1+B2)h/2, to get the area of each side, then multiply by 4 to get the lateral area since there are 4 sides. Remember lateral area is just the sides, then surface area is when you include the area of the two bases.

Answer:

[tex]\boxed{(x+7)^2 =-3x^2-14x}[/tex]

Step-by-step explanation:

[tex]4x^2 + 28x + 49 = 0[/tex]

[tex]\sf Subtract \ 3x^2 \ and \ 14x \ from \ both \ sides.[/tex]

[tex]4x^2 + 28x + 49 -3x^2-14x= 0-3x^2-14x[/tex]

[tex]x^2 + 14x + 49 = -3x^2-14x[/tex]

[tex]\sf Factor \ left \ side \ of \ the \ equation.[/tex]

[tex](x+7)^2 =-3x^2-14x[/tex]

Answer:

(x+7)² = -3x² -14x

Step-by-step explanation:

4x^2 + 28x + 49 = 0

Subtract 3x² and 14x from each sides.

x^2 + 14x + 49 = -3x² -14x

Next step will be factoring.

(x+7)² = -3x² -14x

Answer:

18.711

Step-by-step explanation:

Volume = L * W * H

V = 1.08 * 5.25 * 3.3

1.08 * 5.25 = 5.67

5.67 * 3.3 =

V = 18.711

Answer:

A an increase in m cause n to increase

Step-by-step explanation:

a positive correlation means they will travel in the same direction when one is affected.

Answer:

Option A: An increase in m causes n to increase.

Step-by-step explanation:

A Positive correlation is a relationship between two variables in which both variables move with the same ratio. A positive correlation exists when one variable increases as the other variable increases, or vice-versa.

A perfect positive correlation means that both variables move by the exact same percentage.

Therefore, if there is a strong positive correlation between m and n then  V increases and, w tends to increase.

                           Hope this helped :)

Answer:

Step-by-step explanation:

Probability is the likelihood or chance that an event will occur.

Probability = expected outcome of event /total outcome

Since the population consists of 100 elements, the total outcome of event = 100.

If random sample of 20 element is drawn from the population, the expected outcome = 20

On the first selection, the probability of any particular element being selected = 20/100 = 1/5

Answer:

  181 million km

Step-by-step explanation:

"Correct to the nearest unit" means the actual value might be 1/2 unit larger (or smaller) than the reported value.

The upper bound would be the product of the maximum number of bicycles and the maximum distance each travels:

  (72.5 · 10^6 bicycles)(2.5 km/bicycle) = 181.25 · 10^6 km

__

Since the given numbers are good to 2 significant figures (or so), we might reasonably put the upper bound as 180·10^6 km.

Answer:

A. 10%

B. Lower limit= 21

Upper limit = 39

Step-by-step explanation:

Mean = 30

SD = 3

a. COV = SD/|x| × 100

= 3/30 × 100

= 10%

= 0.1

B. For 88.9 chevbychev interval:

= (1 - 1/K²) = 0.889

= 1/K² = 1 - 0.889

= 1/K² = 0.111

= K² = 1/0.111

= K² = 9

= K = √9

K = 3

Lower limit = 30 - 3(3)

Lower limit = 21

Upper limit = 30 + 3(3)

Upper limit = 39

Therefore lower limit is 21 and upper limit is 39

Answer:

Slope : 2

slope-intercept: y = 2x + 6

Point-slope (as asked): y - 4 = 2 (times) (x + 1)

standered: 2x - y = -6

Step-by-step explanation:

Answer:

Step-by-step explanation:

∠a is alternate interior angle to ∠ECD

∠b is alternate interior angle to ∠BCD

so:

If AB || CD then:

m∠a = m∠ECD = 25° + 42° = 67°

m∠b = 42°

Answer:

Step-by-step explanation:

[tex] \frac{x + 4}{3} = 2[/tex]

To solve it first of all cross multiply

That's

x + 4 = 6

Move 4 to the right side of the equation

The sign changes to negative

That's

x = 6 - 4

We have the final answer as

Hope this helps you

first polygon

ext. angle=180°-120°

=60°

[tex]ext \: ang = \frac{360}{n} [/tex]

n=360°/60°

n=6

second polygon

n=2(6)=12

ext. ang= 360°/n = 360°/12° = 30°

int. ang = 180°-30°= 150°

answer is C

If the ratio of the numbers of sides of two regular polygons is 1:2 and each interior angle of first angle is 120° then the measure of each interior angle of the second polygon is 150° which is option 3).

A regular polygon is a polygon whose all sides are equal to each other.

We have been given ratio of sides of two polygon that is 1:2 and the interior angle of first polygon that is 120 degrees.

Exterior angle will be 180-120=60°

We know that exterior angle =360/n where n is the sides of the polygon.

60=360/n

n=360/60

n=6

Number of sides of other polygon=2*6=12

Exterior angle=360/n

=360/12

=30

Interior angle=180-30=150°

Hence the interior angle of the second polygon is 150 degrees.

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