Use the following definition of absolute value to prove the given statements: If x is a real number, then the absolute value of x , | x | , is defined by: | x | = { x if x ≥ 0 − x if x < 0 For any real number x , | x | ≥ 0 . Moreover, | x | = 0 implies x = 0 . For any two real numbers x and y , | x | ⋅ | y | = | x y | . For any two real numbers x and y , | x + y | ≤ | x | + | y | .

Answers

Answer 1

Answer:

Proved all parts below.

Step-by-step explanation:

As given ,

|x| = [tex]\left \{ {{x , x\geq 0} \atop {-x, x< 0}} \right.[/tex]

To prove- a) For any real number x , | x | ≥ 0 . Moreover, | x | = 0 ⇒ x = 0

                 b) For any two real numbers x and y , | x | ⋅ | y | = | x y | .

                 c) For any two real numbers x and y , | x + y | ≤ | x | + | y | .

Proof -

a)

As given x is a real number

Also , by definition of absolute value of x , we get

| x | ≥ 0

Now,

if |x| = 0

⇒ x = 0 and -x = 0

⇒ x = 0 and x = 0

⇒ x = 0

∴ we get

| x | = 0 ⇒  x = 0

Hence proved.

b)

To prove - | x | ⋅ | y | = | x y |

As we have,

|x| = [tex]\left \{ {{x , x\geq 0} \atop {-x, x< 0}} \right.[/tex]

|y| = [tex]\left \{ {{y , y\geq 0} \atop {-y, y< 0}} \right.[/tex]

|xy| = [tex]\left \{ {{xy , x,y > 0 and x,y < 0} \atop {-xy, x > 0, y< 0 and x <0 , y > 0}} \right.[/tex]

We have 4 cases : i)  when x > 0 , y > 0

                              ii) when x > 0 , y < 0

                              iii) when x < 0, y > 0

                              iv) when x < 0, y < 0

For Case I - when x > 0 , y > 0

⇒ |x| = x, |y| = y

⇒|x|.|y| = xy

For Case Ii - when x > 0 , y < 0

⇒ |x| = x, |y| = -y

⇒|x|.|y| = -xy

For Case Iii - when x < 0 , y > 0

⇒ |x| = -x, |y| = y

⇒|x|.|y| = -xy

For Case IV - when x < 0 , y < 0

⇒ |x| = -x, |y| = -y

⇒|x|.|y| = (-x)(-y) = xy

∴ we get , from all 4 cases

| x | ⋅ | y | = | x y |

Hence Proved.

c)

To prove - | x + y | ≤ | x | + | y |

Let

|x| = |x + y - y|

    ≥ |x + y| - |y|     ( Triangle inequality)

⇒ |x| + |y| ≥ |x + y|

Hence Proved.


Related Questions

5. Following data indicates the number of vehicles arrived during past
100 days in a certain tolling station.
Vehicles
No. of days
0 - 10
3
10 - 20
14
20 - 30
53
30-40
20
40 - 50
10
Calculate average number of vehicles in a day,​

Answers

Answer:

what are you supposed to do here?

Step-by-step explanation:

I need help with this one

Answers

Answer:

Yes they are similar

Step-by-step explanation:

They have the same measurements adding up to 180.

Triangle RST angles are 120, 20, and 40

Triangle JKL angles are 120, 40, 20

Those are the same numbers.

The cell phone plan used by Samantha charges her $0.40 per minute in addition to a $30 monthly fee. In January, she spoke for 100 minutes and
was charged $70. How much is she charged for February, when she spoke for 200 minutes?
A
$80
B
$100
$110
$140

Answers

The answer is $110

Explanation: .40*200=80 80+30=110

The point P is on the unit circle. Find P(x, y) from the given information. The x-coordinate of P is 12 13 , and the y-coordinate is negative.

Answers

This question is incomplete, the complete question is;

The point P is on the unit circle. Find P(x, y) from the given information. The x-coordinate of P is 12/13 , and the y-coordinate is negative.

Answer: P( x, y ) = ( -5/13, 12/13 )

Step-by-step explanation:

Given that;

p( x, y ) is on the unit circle,

Radius of the circle must be 1

so the equation x² + y² = r²

x = 12/13 and r = 1

(12/13)² + y² = 1²

y² = 1 - (12/13)²

y = √ [ 1 - (12/13)² ]

y =  ±5/13

since the y-coordinate is negative y = -5/13

Therefore, P( x, y ) = ( -5/13, 12/13 )

517 37/50 + 312 3/100

Answers

Answer:

Exact form: 32977/100

Decimal form: 829.77

Mixed number form: 829 77/100

Step-by-step explanation:

Find 3.5% of 950 g.

Answers

Answer:

33.25 g

Step-by-step explanation:

Answer:

33.25 g

plz refer to the picture

19 ≥ 3f+1 ≥5 pls help

Answers

Answer:

Hi...u should do like this

18>3f>4

6>f>4/3

The students at Job's high school

were surveyed to determine their

favorite foods. The results are shown

in the table below. Suppose students

were randomly selected and asked

what their favorite food is. Find the

probability of each event. Write as a

fraction in simplest form.


Favorite Food Responses

Pizza 19

Steak 8

Chow-mein 5

Seafood 4

Spaghetti 3

Cereal 1


16. P(steak)

17. P(Spaghetti)

18. P(cereal or seafood)

19. P(not chow-mein)

19. P(pizza)

20. P(cereal or steak)

21. P(not steak) 22. P(not cereal or seafood)

23. P(chicken) 24. P(chow mein or spaghetti)

Answers

Maybe pay attention to school and u would know

unit rate for $112 in 8 hours

Answers

Answer:

$14 per hour could i get brainliest please?

Step-by-step explanation:

Answer:

$14 per hour

Step-by-step explanation:

112 divided by 8 is 14. So $14 per hour

2/3 of a yard = ______ inches

Answers

Answer:

24 inches

Step-by-step explanation:

you're welcome

You buy cheese in 1 pound bags. The recipe for burritos requires 1.7 ounces of cheese per serving. How many servings can you make?

Answers

Since there’s 16 ounces in a pound, you should be able to make 9 servings

Can someone please help me

Answers

Answer:

12:15

3 goes into both of these numbers so then becomes

4:5

cannot be reduced any further

answer

4:5

Mr. Marcus is splitting a huge new pack of colored pencils equally among 25 students after splitting the pencils he has 4 left if there were 429 colored pencils to begin with how many did each student receive

Answers

Answer:

hIm so sorry for that other person they did the same thing to my answer and a bunch of other people too iecked there account and reported him many times so sorry but can give you the answer :)

Its 17 if i id math correctly! sorry bout the other person have a great day

Step-by-step explanation:

A game of chance involves spinning a wheel with 4 number on it. The wheel is designed so that the result of each spin Xhas the following probability distribution. 2 3 Result of a spin .x Probability : 0.50
(a) Find and interpret the mean of X.
(b) Find and interpret the standard deviation of x.
(c) It costs a player $5 for a single spin. The player will receive (in dollars) three times the number that appears. So the profit for one play of this game is Yeur 5. What is the mean and standard deviation of 7

Answers

Distribution table :

X : ___ 1 _____ 2 _____ 3 ______ 4

P(x) __0.50 __0.25 __ 0.15 ____ 0.10

Answer:

1.85 ; 1.014 ;` 0.55 ; 3.042

Step-by-step explanation:

Probability distribution :

X : ___ 1 _____ 2 _____ 3 ______ 4

P(x) __0.50 __0.25 __ 0.15 ____ 0.10

The mean: E(x) = Σ(X * p(x))

(1*0.5) + (2*0.25) + (3*0.15) + (4 *0.10)

= 1.85

Standard deviation = sqrt(Var(x))

Var(x) = Σ(x²*p(x)) - E(x)²

Var(x) = ((1^2*0.5) + (2^2*0.25) + (3^2*0.15) + (4^2 *0.10)) - 1.85^2

= 4.45 - 3.4225

= 1.0275

Standard deviation = sqrt(1.0275)

Standard deviation = 1.0136567

Standard deviation(X) = 1.014

3.)

Cost of spin = $5

Amount, y to be received = 3 times the number that appears

y = 3x - cost of playing

y = 3x - 5

E(y) = E(3x - 5)

E(y) = E(3x) - 5

Recall :E(x) = 1.85

E(y) = 3(1.85) - 5

E(y) = 0.55

Standard deviation :Sd(y) =

Sd(3x - 5)

3(1.014)

= 3.042

6. (CED.2, REI. 6) A manager is comparing
the cost of buying baseball caps from two
different companies.
Company X charges a $50 fee plus S7 per
baseball cap.
Company Y charges a $30 fee plus $9 per
baseball cap.
For what number of baseball caps will the
cost be the same at both companies?
A. 20
B. 10
C. 40
D. 100

Answers

I think the answer for this question is the second one

Need help #1. The answer is shown, but I don’t know how to get to the answer. Please teach and show steps.

Answers

Answer:

B

Step-by-step explanation:

We are given that x and y are functions of time t such that x and y is a constant. So, we can write the following equation:

[tex]x(t)+y(t)=k,\text{ where $k$ is some constant}[/tex]

The rate of change of x and the rate of change of y with respect to time t is simply dx/dt and dy/dt, respectively. So, we will differentiate both sides with respect to t:

[tex]\displaystyle \frac{d}{dt}\Big[x(t)+y(t)\Big]=\frac{d}{dt}[k][/tex]

Remember that the derivative of a constant is always 0. Therefore:

[tex]\displaystyle \frac{dx}{dt}+\frac{dy}{dt}=0[/tex]

And by subtracting dy/dt from both sides, we acquire:

[tex]\displaystyle \frac{dx}{dt}=-\frac{dy}{dt}[/tex]

Hence, our answer is B.

Answer:

Let x and y be functions of time t such that the sum of x and y is constant.

(B) is the right answer

A surf shop charges $6 to rent a wetsuit and $12 per hour to rent a surfboard. Write a function to model the cost, c, to rent a wetsuit and surfboard for h hours.

Answers

Answer:

c(h)=12h+6

because the swimsuit only needs to be paid for once, whereas the surfboard is charged on an hourly basis

EFGH is an isosceles trapezoid. If EG=3y+19 and FH=11y-21, find the value of y.

Answers

Answer:

y = 5

Step-by-step explanation:

The diagonals of the isosceles EFGH are equal. Therefore:

EG = FH

EG = 3y + 19

FH = 11y - 21

Thus:

3y + 19 = 11y - 21

Collect like terms

3y - 11y = -19 - 21

-8y = -40

Divide both sides by -8

y = 5

A student was measuring water in a graduated cylinder. The student read the amount of water at 20 ml. The actual amount of water in the graduated cylinder was 17 ml. What is the approximate percent error?
A.
3%

B.
8%

C.
15%

D.
18%

Answers

The answer is D. 18%

The mean amount purchased by a typical customer at Churchill's Grocery Store is $27.50 with a standard deviation of $7.00. Assume the distribution of amounts purchased follows the normal distribution. For a sample of 68 customers, answer the following questions

a. What is the likelihood the sample mean is at least $30.00?
b. What is the likelihood the sample mean is greater than $26.50 but less than $30.00?
c. Within what limits will 90 percent of the sample means occur?

Answers

Answer:

a) 0.0016 = 0.16% probability that the sample mean is at least $30.00.

b) 0.8794 = 87.94% probability that the sample mean is greater than $26.50 but less than $30.00

c) 90% of sample means will occur between $26.1 and $28.9.

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

When the distribution is normal, we use the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

In this question, we have that:

[tex]\mu = 27.50, \sigma = 7, n = 68, s = \frac{7}{\sqrt{68}} = 0.85[/tex]

a. What is the likelihood the sample mean is at least $30.00?

This is 1 subtracted by the pvalue of Z when X = 30. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem, we have that:

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{30 - 27.5}{0.85}[/tex]

[tex]Z = 2.94[/tex]

[tex]Z = 2.94[/tex] has a pvalue of 0.9984

1 - 0.9984 = 0.0016

0.0016 = 0.16% probability that the sample mean is at least $30.00.

b. What is the likelihood the sample mean is greater than $26.50 but less than $30.00?

This is the pvalue of Z when X = 30 subtracted by the pvalue of Z when X = 26.50. So

From a, when X = 30, Z has a pvalue of 0.9984

When X = 26.5

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{26.5 - 27.5}{0.85}[/tex]

[tex]Z = -1.18[/tex]

[tex]Z = -1.18[/tex] has a pvalue of 0.1190

0.9984 - 0.1190 = 0.8794

0.8794 = 87.94% probability that the sample mean is greater than $26.50 but less than $30.00.

c. Within what limits will 90 percent of the sample means occur?

Between the 50 - (90/2) = 5th percentile and the 50 + (90/2) = 95th percentile, that is, Z between -1.645 and Z = 1.645

Lower bound:

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]-1.645 = \frac{X - 27.5}{0.85}[/tex]

[tex]X - 27.5 = -1.645*0.85[/tex]

[tex]X = 26.1[/tex]

Upper Bound:

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]1.645 = \frac{X - 27.5}{0.85}[/tex]

[tex]X - 27.5 = 1.645*0.85[/tex]

[tex]X = 28.9[/tex]

90% of sample means will occur between $26.1 and $28.9.

Question 9 Multiple Choice Worth 1 points) (03.01 MOO) 13 Simplify​

Answers

[tex] \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \bold{\frac{ \sqrt[4]{ \\ 3} }{ \sqrt[5]{3} } }[/tex]

Note : For a problem like this, all we have to do is Rewrite the problem in exponential form to give us an answer of :

[tex] \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \bold{ {_3}\cfrac{1}{20} }[/tex]

[tex]\therefore[/tex]The correct part of the problem is A) [tex] \bold{ {_3}\cfrac{1}{20} }[/tex]

A rectangular garden has a perimeter of 50cm. The length of one side is 15cm. What is the measurement of the width?​

Answers

Answer:

The measurement of the width is 10cm.

A family buys 5 airline tickets. They also buy travel insurance that is an additional $17 per ticket ($85). The total cost for the 5 tickets plus the insurance is $1,495. Let x represent the price of one ticket. Write and equation to represent the situation. *

Answers

Answer:

The first answer is 5(x+17)=1,495

The second one is $282

Hope this helps

Find the value of x
12
36
18
24
27
36
0 11
9
0 10
012

Answers

Answer:

11

Step-by-step explanation:

I think if I am wrong I am sorry

Ernesto has already baked 3 pies, and he can bake 2 pies with each additional cup of sugar
he buys. Write an equation that shows the relationship between the additional cups of sugar
x and the number of pies y.
Write your answer as an equation with y first, followed by an equals sign.

Answers

Answer:

igcwochcd chocho dhvohov dochvo

Marking brainliest


Stefanie has 18 grams of 20% sugar syrup and john 30 of 25% if Stefanie and john mix the syrups together how many grams of sugar will they have?

Answers

Answer:

[tex]11.1\: \mathrm{g}[/tex]

Step-by-step explanation:

Stefanie's mixture of 18 grams has a 20% sugar content. Therefore, there are [tex]18\cdot 0.2=3.6[/tex] grams of sugar in her syrup.

John's mixture of 30 grams has a 25% sugar content. Therefore, there are [tex]30\cdot 0.25=7.5[/tex] grams of sugar in her syrup.

Therefore, if they mix their syrups together, there will be [tex]3.6+7.5=\fbox{11.1}[/tex]grams of sugar.

Answer:

I need this answer ASAP

Step-by-step explanation:

xy^2-x^2y
x= -1
y= -2​

Answers

Answer:

xy(x-1y)

Step-by-step explanation:

xy^2-x^2y

=solution,

taking common

xy(x-1y)

_____consists of activities that are
not required as part of one's formal
role in the organization
Select one:
a. None of the above
b. Lobbying
c. Influence
d. Political behaviour

= Political behaviour ​

Answers

Step-by-step explanation:

political behaviour consists of activities that are

not required as part of one's formal

role in the organization

Need as soon as possible

Answers

Answer:  136 square feet

=======================================================

Explanation:

The front face is a triangle with base 6 and height 4.

The area is 0.5*base*height = 0.5*6*4 = 12 square feet

The back face is also 12 square feet since the front and back faces are identical triangles.

So far we have 12+12 = 24 square feet of surface area.

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

The bottom face, that runs along the floor or ground, is a rectangle that is 6 ft by 7 ft. So we have 6*7 = 42 square feet of surface area here. This adds onto the 24 we found earlier to get 24+42 = 66 square feet so far.

To find the left and right upper faces, we'll need to find the length of the hypotenuse first. The 6 ft cuts in half to 3 ft. The right triangle on the left has side lengths of 4 ft and 3 ft as the two legs. Use the pythagorean theorem to find the hypotenuse is 5 ft. We have a 3-4-5 right triangle.

This means the upper left face is 5 ft by 7 ft leading to an area of 5*7 = 35 square feet. The same can be said about the upper right face.

So we add on 35+35 = 70 more square feet to the 66 we found earlier to get a grand total of 70+66 = 136 square feet of surface area.

Rewrite the following equation as a function of x
1/16x + 1/320y - 29 = 0
A. F(x) = -9280 + 1/16x
B. F(x) = 9280 - 20x
C. F(x) = -9280 + 20x
D. F(x) = 9280 - 1/16x

Answers

Answer:

the awnser is b hope this helps

Step-by-step explanation:

The equation as a function of x is f(x)=9280-20x. Therefore, option B is the correct answer.

The given function is x/16 + y/320 - 29 = 0.

What is a function?

Functions are the fundamental part of calculus in mathematics. The functions are the special types of relations. A function in math is visualized as a rule, which gives a unique output for every input x. Mapping or transformation is used to denote a function in math. These functions are usually denoted by letters such as f, g, and h. The domain is defined as the set of all the values that the function can input while it can be defined. The range is all the values that come out as the output of the function involved. Co-domain is the set of values that have the potential of coming out as outputs of a function.

Now, the LCM of denominators 16 and 320 is 320.

So, 20x/320 + y/320 - 9,280/320 = 0

⇒20x+y-9280=0

⇒y=9280-20x

The equation as a function of x is f(x)=9280-20x. Therefore, option B is the correct answer.

To learn more about the function visit:

https://brainly.com/question/9046022.

#SPJ2

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