Use the dot product to determine whether v and w are orthogonal.

v=-i-j, w=-i+j

Select the correct choice below and fill in the answer box to complete your choice.

O A. The vectors v and w are not orthogonal because their dot product is ___

O B. The vectors v and w are orthogonal because their dot product is ___

Answer:

F = 585844 N

Step-by-step explanation:

Given that:

A semicircular plate with radius 7 m is submerged vertically in water so that the top is 3 m above the surface.

The objective of this question is to express the hydrostatic force against one side of the plate as an integral and evaluate it.

To start with the equation of a circle:  a² + b² = r²

The equation of  circle with radius r = 7 can be expressed as:

a² + b² = 7²

a² + b² = 49

b² = 49 - a²

b = [tex]\sqrt{49 -a}[/tex]

NOW;

The integral of the hydrostatic force with a semicircular plate with radius 7 m and the top is 3 m above the surface can be calculated as follows:

[tex]\mathtt{F = 2 \rho g \int \limits^7_3 (a -3) \sqrt{49 -y^2} \ \ da}[/tex]

[tex]\mathtt{F = 2 \rho g \begin {pmatrix}\dfrac{\sqrt{49 -a^2} \ (2a^2-9a - 98)-(441 \times sin^{-1} (\dfrac{a}{3})) }{6} \end{pmatrix}}[/tex]

where;

density of water is 1000 kg/m3

and acceleration due to gravity is 9.8 m/s

Solving the integral; we have:

F = 2 ×  1000 kg/m³ × 9.8 m/s × (29.89)

F = 585844 N

Answer:

$50

Step-by-step explanation:

Let x represent the cost of the cell phone.

Since the TV cost 5 times as much as the cell phone, its cost can be represented by 5x.

Since the computer cost 2.5 times as much as the TV, its cost can be represented by 12.5x.

Create an equation to represent the situation, and solve for x:

x + 5x + 12.5x = 925

18.5x = 925

x = 50

So, the cell phone cost $50

Answer:

$50

Step-by-step explanation:

Let x represent the cost of the cell phone.

Since the TV cost 5 times as much as the cell phone, its cost can be represented by 5x.

Since the computer cost 2.5 times as much as the TV, its cost can be represented by 12.5x.

Create an equation to represent the situation, and solve for x:

x + 5x + 12.5x = 925

18.5x = 925

x = 50

So, the cell phone cost $50

Answer:

The frequency distribution does not appear to be normal.

Step-by-step explanation:

The data provided is as follows:

S = {0.38 , 0 , 0.22 , 0.06 , 0 , 0 , 0.21 , 0 , 0.53 , 0.18 , 0 , 0 , 0.02 , 0 , 0 , 0.24 , 0 , 0 , 0.01 , 0 , 0 , 1.28 , 0.24 , 0 , 0.19 , 0.53 , 0 , 0, 0.24 , 0}

It is provided that the first lower class limit should be 0.00 and the class width should be 0.20.

The frequency distribution table is as follows:

Class Interval  Count

 0.00 - 0.19            21

 0.20 - 0.39             6

 0.40 - 0.59             2

 0.60 - 0.79             0

 0.80 - 0.99             0

  1.00 - 1 . 19             0

  1.20 - 1. 39             1

The frequency distribution does not appear to be normal. This is because the frequencies does not start and end at almost equivalent points and the mid-distribution does not consist of the highest frequency.

Thus, the frequency distribution does not appear to be normal.

Answer:

[tex] - 8 = 8( - 3 + a) \\ - 8 = - 24 + 8a \\ 8a = 16 \\ a = 2[/tex]

Answer:

2

Step-by-step explanation:

-8 = 8a - 24

16 = 8a

a =2

Answer:

x = -6

y = 4

Step-by-step explanation:

Rewriting the equations :

Now, solving the two equations using substitution method, we get :

x = -6

y = 4

Answer:

y = 4

x = -6

Step-by-step explanation:

1/2 x + 1/4 y= -2        first equation

-2/3 x + 1/2 y = 6      second equation

solution:

from the first equation:

8(1/2 x + 1/4 y) = -2*8

8x*1/2 + 8y*1/4 = -16

8x/2 + 8y/4 = -16

4x + 2y = -16        third equation

from the second equation

6(-2/3 x + 1/2 y) = 6*6

6x*-2/3 + 6y*1/2 = 36

-12x/3 + 6y/2 = 36

-4x + 3y = 36        fourth equation

from the third & fourth equation:

 4x + 2y  = -16

-4x + 3y  = 36

   0  + 5y = 20

5y = 20

y = 20/5

y = 4

from the fourth equation:

-4x + 3y = 36

-4x + 3*4 = 36

-4x + 12 = 36

-4x = 36 - 12

-4x = 24

x = 24/-4

x = -6

Check:

from the first equation:

1/2 x + 1/4 y = -2

1/2 *-6 + 1/4 * 4 = -2

-3 + 1 0 -2

from the second equation:

-2/3 x + 1/2 y = 6

-2/3 * -6  +  1/2 * 4 = 6

4 + 2 = 6

Answer:

[tex]a\cdot b[/tex] = 1

Step-by-step explanation:

Given that,

Vector [tex]a=5i+7j[/tex]

Vector [tex]b=-4i+3j[/tex]

We need to find [tex]a{\cdot} b[/tex] means the dot product of a and b. So,

[tex]a{\cdot} b=(5i+7j){\cdot} (-4i+3j)[/tex]

We know that,

[tex]i{\cdot}i, j{\cdot}j,k{\cdot}k=1\ \text{and}\ i{\cdot}j= j\cdot i=0[/tex]

So,

[tex]a{\cdot} b=(5i+7j){\cdot} (-4i+3j)\\\\=5i{\cdot}(-4i)+5i{\cdot} 3j+7j\cdot(-4i)+7j\cdot 3j\\\\=-20+21\\\\=1[/tex]

So, the value of [tex]a\cdot b[/tex] is 1.

Answer:

1

Step-by-step explanation:

9514 1404 393

Answer:

  210 minutes

Step-by-step explanation:

Jason's rate of peeling is ...

  (15 potatoes)/(25 minutes) = 15/25 potatoes/minute = 3/5 potatoes/minute

Janette's rate of peeing potatoes is ...

  (8 potatoes)/(6 minutes) = 4/3 potatoes/minute

Their combined rate is ...

  (3/5 +4/3) = (9 +20)/15 = 29/15 . . . . potatotes/minute

Then the time required for 406 potatoes is ...

  (406 potatoes)/(29/15 potatoes/minute) = (406×15/29) minutes

  = 210 minutes

Answer:

Step-by-step explanation:

a. What test is appropriate for this analysis?

A Chi-square  test of independence is appropriate for this analysis because it is used to compare two variables or testing relationship on categorical variables.  

b. State the null hypothesis:

The null hypothesis is the default hypothesis

[tex]\mathtt{H_o:}[/tex] There is no particular preference for any brand of toothpaste among students.

c. State the alternative hypothesis:

The alternative hypothesis is the research hypothesis which comes in place to challenge the validity of the null hypothesis.

[tex]\mathtt{H_a:}[/tex] There is particular preference for brands of toothpaste among students.

d. Find the critical value:

degree of freedom = n-1

degree of freedom = 3 - 1

degree of freedom = 2

At the level of significance ∝ = 0.05

The confidence interval = 0.95 and degree of freedom = 2, the critical value from the chi-square distribution table = 5.991

e. Calculate the test statistic:

Using the chi square test statistics; we have the following:

Crest             Colgate            Aquafresh            Total

24                        13                     8                      45

Since we have three brands. Then, for each brand, the expected value

= Total /3

= 45/3

=15

Thus:

Chi -square [tex]\mathtt{X^2 = \dfrac{(observed \ value - expected \ value)^2}{expected \ value}}[/tex]

[tex]\mathtt{X^2 = \dfrac{(24 - 15)^2}{15} + \dfrac{(13 - 15)^2}{15} + \dfrac{(8 - 15)^2}{15} }[/tex]

[tex]\mathtt{X^2 = \dfrac{81}{15} + \dfrac{4}{15} + \dfrac{49}{15} }[/tex]

[tex]\mathtt{X^2 = \dfrac{81+4+49}{15}}[/tex]

[tex]\mathtt{X^2 = \dfrac{134}{15}}[/tex]

[tex]\mathtt{X^2 =8.93 }[/tex]

f. Make a decision:

Since the chi-square value is greater than the critical value , we reject the null hypothesis and conclude that the students have  particular preference for brands of toothpaste.

By the supplementary angles theorem, we know that both of the angles add up to equal 180°, so:

(4x + 22) + (8x - 10) = 180

12x + 12 = 180

12x = 168

x = 14

Now you just have to plug in x into the value for ∠ABC:

∠ABC = 4x + 22

∠ABC = 4(14) + 22

∠ABC = 46 + 22

∠ABC = 68°

Answer:

D = 78

Step-by-step explanation:

The two angles form a straight line so they add to 180

4x+22 + 8x-10 = 180

Combine like terms

12x +12 =180

Subtract 12 from each side

12x+12-12 = 180-12

12x = 168

Divide by 12

12x/12 =168/12

x=14

We want to find ABC

4x+22 = 4*14+22 = 56+22 = 78

Answer:

3)Maria is running a profitable business.

4)Maria’s total revenue exceeds her total profit.

Step-by-step explanation:

The graph shows variation of revenue and cost with respect to price of product and not with respect to time .

The price of the product is 2.30 . From this graph , we see  that at this price revenue exceeds total cost . So maria is running a profitable business .

Total profit can not exceed total revenue as

Total revenue - total cost = total profit .

So total profit will always be less than total revenue .

Answer:

The question is not complete, below is the complete question:

What is meant by the term 90% confident? when constructing a confidence interval for a mean?

a. If we took repeated samples, approximately 90% of the samples would produce the same confidence interval.

b. If we took repeated samples, approximately 90% of the confidence intervals calculated from those samples would contain the sample mean.

c. If we took repeated samples, approximately 90% of the confidence intervals calculated from those samples would contain the true value of the population mean.

d. If we took repeated samples, the sample mean would equal the population mean in approximately 90% of the samples.

Answer:

The correct answer is:

If we took repeated samples, approximately 90% of the confidence intervals calculated from those samples would contain the true value of the population mean.  (c)

Step-by-step explanation:

a 90% confidence level means that if repeated samples were taken, 9 out of 10 times, the confidence intervals of the sample chosen will be close to the mean (true value), which is a true representation of the population parameter. when using confidence intervals, there are always margins of allowable accuracy, and this is suggested by using standard diviations snd variances.

I attached a simple document to this answer that will give you more insight into confidence intervals used in statistics.

Answer:

a) 20, 21, 28 : acute

b) 3, 6, 4 : obtuse

c) 8, 12, 15 : obtuse

Step-by-step explanation:

You can see if a triangle is acute, obtuse, or right using the Pythagorean theorem as follows:

If [tex]a^2+b^2=c^2[/tex] , then the triangle is right.

If [tex]a^2+b^2>c^2[/tex] , then the triangle is acute.

If [tex]a^2+b^2<c^2[/tex] , then the triangle is obtuse.

Solve each to find if the given lengths form an acute, obtuse, or right triangle ( The biggest number is the hypotenuse length, since the hypotenuse is always the longest side in a triangle. This is represented by c):

a) 20, 21, 28

Insert numbers, using 28 as c:

[tex]20^2+21^2[/tex]_[tex]28^2[/tex]

Simplify exponents ([tex]x^2=x*x[/tex]):

[tex]400+441[/tex]_[tex]784[/tex]

Simplify addition:

[tex]841[/tex]_[tex]784[/tex]

Identify relationship:

[tex]841>784[/tex]

The sum of the squares of a and b is greater than the square of c. This triangle is acute.

b) 3, 6, 4

Insert numbers, using 6 as c:

[tex]3^2+4^2[/tex]_[tex]6^2[/tex]

Simplify exponents:

[tex]9+16[/tex]_[tex]36[/tex]

Simplify addition:

[tex]25[/tex]_[tex]36[/tex]

Identify relationship:

[tex]25<36[/tex]

The sum of the squares of a and b is less than the square of c. This triangle is obtuse.

c) 8, 12, 15

Insert numbers, using 15 as c:

[tex]8^2+12^2[/tex]_[tex]15^2[/tex]

Simplify exponents:

[tex]64+144[/tex]_[tex]225[/tex]

Simplify addition:

[tex]208[/tex]_[tex]225[/tex]

Identify relationship:

[tex]208<225[/tex]

The sum of the squares of a and b is less than the square of c. This triangle is obtuse.

:Done.

The correct values are,

a) 20, 21, 28  = Acute

b) 3, 6, 4  = Obtuse

c) 8, 12, 15 = Obtuse

A triangle is a three sided polygon, which has three vertices and three angles which has the sum 180 degrees.

Given that;

The sides are,

a) 20, 21, 28

b) 3, 6, 4

c) 8, 12, 15

Now,

We know that;

If three sides of a triangle are a, b and c.

Then, We get;

If a² + b² = c², then the triangle is right triangle.

If a² + b² > c², then the triangle is acute triangle.

If a² + b² < c², then the triangle is obtuse triangle.

Here, For option a;

⇒ 20, 21, 28

Clearly, a² + b² = 20² + 21²

                       = 400 + 441

                       = 841

And, c² = 28² = 784

Thus, a² + b² > c²

Hence, It shows the acute angle.

For option b;

⇒ 3, 6, 4

Clearly, a² + b² = 3² + 4²

                       = 9 + 16

                       = 25

And, c² = 6² = 36

Thus, a² + b² < c²

Hence, It shows the obtuse angle.

For option c;

⇒ 8, 12, 15

Clearly, a² + b² = 8² + 12²

                       = 64 + 144

                       = 208

And, c² = 15² = 225

Thus, a² + b² < c²

Hence, It shows the obtuse angle.

Learn more about the triangle visit:

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Answer:

x = -264/35

y = -36/5

Step-by-step explanation:

-6y + 11y = -36

-4y + 7x = -24

Solve for y in the first equation.

-6y + 11y = -36

Combine like terms.

5y = -36

Divide both sides by 5.

y = -36/5

Plug y as -36/5 in the second equation and solve for x.

-4(-36/5) + 7x = -24

Expand brackets.

144/5 + 7x = -24

Subtract 144/5 from both sides.

7x = -264/5

Divide both sides by 7.

x = -264/35

Answer: -264/35

Step-by-step explanation:

i did my work on a calculator

Answer:

B = A/5h - b; You could use

B = (A - 5hb)/5h  This just puts everything over a common denominator.

Step-by-step explanation:

A = 5h (B + b)          Divide both sides by 5h

A/5h = B + b             Subtract b from both sides.

A/5h - b = B

The answer is 670.408, because 6x100=600, 7x10=70, 4x1/10 as a decimal is 0.4, 8x1/1,000 as a decimal is 0.008. Then, you add all of those [tex]600+70+0.4+0.008=670.408[/tex].

Answer:

101,000>1,100

Step-by-step explanation:

101,000>1,100

Answer:

101,000>1,100

Step-by-step explanation:

Answer:

1.24

Step-by-step explanation:

oahsofhasdf0as0dfadera

Lets do

[tex]\\ \sf\longmapsto K=\dfrac{AB}{A+B}[/tex]

[tex]\\ \sf\longmapsto \dfrac{1}{K}=\dfrac{A+B}{AB}[/tex]

[tex]\\ \sf\longmapsto \dfrac{1}{K}=\dfrac{1}{A}+\dfrac{1}{B}[/tex]

[tex]\\ \sf\longmapsto \dfrac{1}{B}=\dfrac{1}{K}-\dfrac{1}{A}[/tex]

[tex]\\ \sf\longmapsto \dfrac{1}{B}=\dfrac{K-A}{AK}[/tex]

[tex]\\ \sf\longmapsto B=\dfrac{AK}{K-A}[/tex]

[tex]\\ \sf\longmapsto 122^2[/tex]

[tex]\\ \sf\longmapsto (100+22)^2[/tex]

[tex]\\ \sf\longmapsto 100^2+2(100)(22)+22^2[/tex]

[tex]\\ \sf\longmapsto 10000+4400+484[/tex]

[tex]\\ \sf\longmapsto 14400+484[/tex]

[tex]\\ \sf\longmapsto 14884[/tex]

112²

(a + b)² = (a² + 2ab + b²)

⇛122²

⇛(100 + 22)²

⇛(100)² + 2 × 100 × 22 + (22)²

⇛10000 + 4400 + 484

⇛14400 + 484

⇛14884

Answer:

angle HGD

Step-by-step explanation:

alternate angles are in Z position

Answer:

(x-7) and (x+12) are the factors and the rest are non factors...

Answer:

38 cm^2

Step-by-step explanation:

The surface area of a rectangular prism is

SA = 2(lw+wh+lh) where h is the height l is the length and w is the width

SA = 2( 3*1 + 3*4+4*1)

    = 2(3+12+4)

   = 2(19)

   = 38 cm^2

Answer:

2/3???

.................

Answer:

0.804% to 3 dec places.

Step-by-step explanation:

If the first 4 throws are a dot and the next 2 are not:

Probability = (1/6)^4 * (5/6)^2

=  25/46656

There are 6C4 ways for this to happen

6C4 = (6*5*4*3)/ (4*3*2*1) = 15 ways.

So The required probability = (25*15)/46656

= 125/15552

= 0.00804

= 0.804%

Answer:

Step-by-step explanation:

Out of 12 consecutive integers:

Sum of 3 integers will be divisible by 4 if the remainders are:

So total number of combinations is:

The  maturity value of a 45-day note for $1,250 dated May 23 and bearing interest 8% is $1,262.5

Using this formula

Maturity value=Principal amount+ Interest

Let plug in the formula

Maturity value=$1,250+($1,250*8%*45 days/360 days)

Maturity value=$1,250+$12.5

Maturity value=$1,262.5

Inconclusion the maturity value is $1,262.5

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Answer: He was given $75 for his birthday

Step-by-step explanation:

The y - intercept represents the rate of which the money is being deposited in the account.

"An equation is said to be linear equation in two variables if it is written in the form of ax + by + c=0, where a, b & c are real numbers and the coefficients of x and y, i.e a and b respectively, are not equal to zero."

"The solution of linear equations in two variables, ax+by = c, is a particular point in the graph, such that when x-coordinate is multiplied by a and y-coordinate is multiplied by b, then the sum of these two values will be equal to c.

Basically, for linear equation in two variables, there are infinitely many solutions."

The given equation is y = 50x + 75

The y intercept represents the amount of money to be deposited in account. The rate of change of money in the account with represent to the months.

Hence, y represents money deposited in the account.

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Answer:c

Step-by-step explanation:

Answer: The answer is C.

Hope this helps you!

Step-by-step explanation:

There is 1 root at x = 1, where the function crosses the x-axis.

There are 2 roots at x = -2, where the function touches the x-axis but does not cross.

So there are 3 real roots total.

The function is:

y = (x − 1) (x − (-2))²

y = (x − 1) (x + 2)²

Using concepts of circles, it is found that the angle measure of each slice is of 72º.

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

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

5 equal slices, thus:

[tex]\frac{360}{5} = 72[/tex]

The angle measure of each slice is of 72º.

A similar problem is given at https://brainly.com/question/16746988

Answer:

Note that orthogonal to the plane means perpendicular to the plane.

Step-by-step explanation:

-1x+3y-3z=1 can also be written as -1x+3y-3z=0

The direction vector of the plane -1x+3y-3z-1=0 is (-1,3,-3).

Let us find a point on this  line for which the vector from this point to (0,0,5) is perpendicular to the given line. The point is x-0,y-0 and z-0 respectively

Therefore, the vector equation is given as:

-1(x-0) + 3(y-0) + -3(z-5) = 0

-x + 3y + (-3z+15) = 0

-x + 3y -3z + 15 = 0

Multiply through by - to get a positive x coordinate to give

x - 3y + 3z - 15 = 0