Let U be a matrix where u_ij = 0 if i > j, and L be a matrix where l_ij = 0 if i < j.
(a) U is called an upper triangular matrix and L is a lower tri-angular matrix. Explain why.
(b) Prove or disprove: The sum of two upper triangular matrices is an upper triangular matrix.
(c) Prove or disprove: The product of two upper triangular matrices is an upper triangular matrix.

Answers

Answer 1

Answer:

A) U is called an upper triangular matrix because all entries below the principal diagonal element are zeros ( 0 )   since Uij = 0 if i >j  also

L is a lower triangular matrix because all entries above the principal diagonal element are zero ( 0 )

B) sum of two upper triangular matrices = upper triangular matrix.

C) product of two upper triangular matrices = upper triangular matrix

Step-by-step explanation:

A) U is called an upper triangular matrix because all entries below the principal diagonal element are zeros ( 0 )   since Uij = 0 if i >j  also

L is a lower triangular matrix because all entries above the principal diagonal element are zero ( 0 ) since Lij = 0  if i < j

B) To prove that sum of two upper triangular matrices

attached below

C) Prove or disprove that product of two upper triangular matrices is an upper triangular matrix

attached below


Related Questions

The composition of a US dollar bill is 3/4 cotton and 1/4 linen. What percent of a dollar bill is cotton?

Answers

Answer:

75% cotton

Step-by-step explanation:

3/4=75%

1/4=25%

total 100%

Determine the x- and y- intercepts for the graph defined by the given equation. y = 7x + 3 a. x-intercept is ( 3, 0) y-intercept is (0, negative StartFraction 3 Over 7 EndFraction) c. x-intercept is (0, negative StartFraction 3 Over 7 EndFraction) y-intercept is ( 3, 0) b. x-intercept is (negative StartFraction 3 Over 7 EndFraction, 0) y-intercept is (0, 3) d. x-intercept is (3, 0) y-intercept is (negative StartFraction 3 Over 7 EndFraction, 0)

Answers

Answer:

x-intercept is (-3/7, 0) and the y-intercept is at (0, 3)

Step-by-step explanation:

Given the function y = 7x + 3

The x-intercept occurs at y = 0. Substituting y = 0 into the expression, we will have:

0 = 7x + 3

7x + 3 = 0

7x = -3

x = -3/7

Similarly, the y-intercept occurs at x = 0. Substituting x = 0 into the expression, we will have:

y = 7(0) + 3

y = 0 + 3

y = 3

Hence the x-intercept is (-3/7, 0) and the y-intercept is at (0, 3)

A random sample of 49 measurements from a population with population standard deviation σ1 = 4 had a sample mean of x1 = 11. An independent random sample of 64 measurements from a second population with population standard deviation σ2 = 5 had a sample mean of x2 = 14. Test the claim that the population means are different. Use level of significance 0.01. What distribution does the sample test statistic follow? Explain.

Answers

Answer:

Reject H0 and conclude that population means are different.

Step-by-step explanation:

H0: μ1 = μ2

H1: μ1 ≠ μ2

x1 = 11 ; σ1 = 4 ; n1 = 49

x2 = 14 ; σ2 = 5 ; n2 = 64

The test statistic :

(x1 - x2) / sqrt[(σ1²/n1 + σ2²/n2)]

Test statistic :

(11 - 14) / sqrt[(4²/49 + 5²/64)]

Test statistic :

-3 / √0.7171556

Test statistic = - 3.542

Using α = 0.01

The critical value Zα/2 ; Z0.01/2 = 2.58

Decison region :

Reject H0 : if Test statistic < Zcritical

Reject H0 : - 3.542 < - 2.58

what is the domain of f(x)=3x/x-1​

Answers

Interval Notation:
(−∞,1)∪(1,∞)
Set-Builder Notation: {x|x≠1}

A spinner is divided into 6 equal parts. These sections are labeled with a number 1, one section has a 2, one section has a 3, and one section has a 4. If the spinner is spun two times, what is the probability it will land on both 2 sides?

Answers

Answer:

[tex]\frac{1}{36} = 0.0278[/tex] = 2.78% probability it will land on both 2 sides.

Step-by-step explanation:

For each trial, there are only two possible outcomes. Either it lands on 2, or it does not. The probability of the spinner landing on two in a trial is independent of any other trial, which means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

One of the six sides is 2:

This means that [tex]p = \frac{1}{6}[/tex]

If the spinner is spun two times, what is the probability it will land on both 2 sides?

This is P(X = 2) when n = 2. So

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 2) = C_{2,2}.(\frac{1}{6})^{2}.(\frac{5}{6})^{0} = \frac{1}{36} = 0.0278[/tex]

[tex]\frac{1}{36} = 0.0278[/tex] = 2.78% probability it will land on both 2 sides.

Solve for x in this equation: 3/4+|5-x|=13/4

Answers

The answer is -5/7
Find the lcm of the denominator
And then use the lcm to multiple

Use the Wilcoxon matched-pairs signed rank test to determine whether there is a significant difference between the related populations represented by the data below. Assume a 5% level of significance and (differences = before - after).

Before After
5.6 6.4
1.3 1.5
4.7 4.6
3.8 4.3
2.4 2.1
5.5 6.0
5.1 5.2
4.6 4.5
3.7 4.5

a. What is the value of T= 36.5 is wrong
b. What is the value of T= 8.5 is wrong
c. What is the test statistic, T= 5 is wrong

Answers

Answer:

We fail to reject the null and conclude thattherw is no difference in population means.

Step-by-step explanation:

Before After

5.6 6.4

1.3 1.5

4.7 4.6

3.8 4.3

2.4 2.1

5.5 6.0

5.1 5.2

4.6 4.5

3.7 4.5

H0 : There is no difference in population

H1 : There population are not all equal

Difference, d = (Before - After)

d = -0.8, -0.2, 0.1, -0.5, 0.3, -0.5, -0.1, 0.1, -0.8

The test statistic :

T = dbar / (Sd/√n)

dbar = Σx / n = - 2.4 / 9 = 0.2666

Standard deviation of difference Sd; [√Σ(d - dbar)² / n-1]

Sd = 0.403 (using calculator)

Hence,

T = dbar / (Sd/√n)

-0.266 / (0.403/√9)

-0.266 / 0.1343333

= - 1.980

The Pvalue ;

df = n - 1 ; 9 - 1 = 8

Pvalue(-1.980, 8) = 0.083

α = 0.05

Since Pvalue > α; We fail to reject the null and conclude thattherw is no difference in population means.

I need help with this ​

Answers

Answer:

A.

Step-by-step explanation:

A for apple....

Dwuhhhhhhhhhhhhh

Isss ezeewer dan anytwing

Find the volume of the cylinder in terms of [tex]\pi[/tex].

h = 6 and r = 3.


a. 27[tex]\pi[/tex] in.³

b. 108[tex]\pi[/tex] in.³

c. 54[tex]\pi[/tex] in.³

d. 324[tex]\pi[/tex] in.³

Answers

Answer:

c. 54[tex]\pi[/tex] in.³

The volume of cylinder is 54[tex]\pi[/tex] in.³

Step-by-step explanation:

Given that :-

Height of cylinder , h = 6.Radius of cylinder, r = 3.

To Find :-

Volume of cylinder.

Solution:-

We use formula

Volume of cylinder = π × (radius)² × h

Substitute the value of radius and height.

Volume of cylinder = π × ( 3)² × 6.

Evaluate the exponent.

Volume of cylinder = π × 9 × 6.

Multiply we get ,

Volume of cylinder = 54[tex]\pi[/tex] in.³

The formula we use,

→ Volume of cylinder = π × r² × h

It is given that,

→ Height (h) = 6 and radius (r) = 3.

Then we have to,

find the volume of the cylinder,

→ π × r² × h

→ π × 3² × 6

→ π × 9 × 6

→ 54π in.³

Thus, option (c) is the answer.

If x+y=6 and xy =2find x³+y³(please help me fast with explanation also please) T^T​

Answers

Answer: x³+y³=180

Step-by-step explain:                                                                                            let's remember the formula                                                                                 x³+y³=(x+y)(x²-xy+y²) and also  x³+y³=(x+y)³-3xy(x+y)                                              then                                                                                      [tex]\displaystyle\boldsymbol{ x^3+y^3=\underbrace{(x+y)^3}_{6}-3\underbrace{xy}_{2}\underbrace{(x+y)}_6}=\\\\6^3-3\cdot 2\cdot 6=216-36=180[/tex]                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                

5.For the function define by :

Please help

Answers

Answer:

Step-by-step explanation:

The breaking point for the graph (if there was one), is one. That means at one the function you use changes.

It goes from x^2 to 2x + 1

Answer A

Here's the catch. Where is 0? Zero is less than one. So what do you use? The answer is that f(x) = x^2

Answer B

if f(x) = x^2 then wherever you see an x, you put in 0.

f(x) = x^2

f(0) = 0^2

You could multiply 0 by itself a million times and it would still get 0.

f(0) = 0

A researcher considers two methods for collecting data to determine if store-brand laundry detergents work as well as name-brand detergents.


Method 1: The researcher surveys shoppers as they enter a grocery store. The shoppers are asked which type of detergent they use and then rate the cleanliness of their laundry on a scale from 1 to 10 (with 10 being the cleanest). The ratings of the name-brand detergents are compared to the ratings of the store-brand detergent.


Method 2: The researcher creates 10 loads of soiled fabrics and washes 5 of the loads with name-brand detergent and the other 5 with store-brand detergent. Volunteers are asked to assess the cleanliness of the fabrics using a scale from 1 to 10 (with 10 being the cleanest), and the ratings of the name-brand detergents are compared to the ratings of the store-brand detergent.


Which method describes an observational study?


Method 2 is an observational study because volunteers assess the fabrics.

Method 1 is an observational study because many people can be surveyed.

Method 1 is an observational study because no attempt is made to influence results.

Both methods are observational studies because information on both types of detergent can be collected.


Not A.

Answers

Answer:

C. Method 1 is an observational study because no attempt is made to influence results.

Step-by-step explanation:

Based on the descriptions provided: Method 1 is an observational study because no attempt is made to influence the results. Option 3 is the correct answer.

An observational study is a type of study where researchers observe and collect data without actively intervening or manipulating any variables.

Method 1 involves surveying shoppers and asking them about their detergent use and laundry cleanliness ratings. The researcher is merely collecting data without intervening or manipulating any variables. The study relies on the natural behavior of shoppers and their responses.

Method 2, on the other hand, involves actively creating soiled fabrics and washing them with different detergents. This intervention introduces an element of manipulation, making it more of an experimental study than an observational one.

To know more about observational study :

https://brainly.com/question/29141360

#SPJ3

A small manufacturing company recently instituted Six Sigma training for its employees. Two methods of training were offered: online and traditional classroom. Management was interested in whether the division in which employees worked affected their choice of method. Below is a table summarizing the data.

Sales Quality Operations Total
Traditional 16 10 8 34
Online 35 23 44 102
Total 51 33 52 136

Required:
a. What is the probability that an employee chose online training?
b. What is the probability that an employee is in the Quality division and chose online training?
c. What is the probability that an employee chose online training given that he/she is in the Sales division?

Answers

Answer:

(a) [tex]P(Online\ Training) = 0.750[/tex]

(b) [tex]Pr = 0.169[/tex] --- Quality Division and Online Training

(c) [tex]P(A\ |\ B) = 0.686[/tex] --- Online Training given Sales Division

Step-by-step explanation:

Given

The two-way table

Solving (a): P(Online Training)

The total employee is:

[tex]Total = 136[/tex]

The employees for online training is:

[tex]Online\ Training = 102[/tex]

So, the probability is:

[tex]P(Online\ Training) = \frac{102}{136}[/tex]

[tex]P(Online\ Training) = 0.750[/tex]

Solving (b): P(Quality Division and Online Training)

The number of employees that choose quality Division and online training is 23

So, the probability is:

[tex]Pr = \frac{23}{136}[/tex]

[tex]Pr = 0.169[/tex]

Solving (c): P(Online Training | Sales Division)

This is calculated as:

Let:

[tex]A \to[/tex] Online training

[tex]B \to[/tex] Sales division

So, we have:

[tex]P(A\ |\ B) = \frac{n(A\ n\ B)}{n(B)}[/tex]

From the table:

[tex]n(A\ n\ B) =35[/tex]

[tex]n(B) = 16 + 35 = 51[/tex]

So, the probability is:

[tex]P(A\ |\ B) = \frac{35}{51}[/tex]

[tex]P(A\ |\ B) = 0.686[/tex]

A ladder is leaning against a building so that the distance from the ground to the top of the latter is 1 foot less than the length of the latter find the length of the latter is the distance from the bottom of the ladder to the building is 7 feet

Answers

Answer:

[tex]25\text{ feet}[/tex]

Step-by-step explanation:

The ladder, ground, and building form a right triangle where the vertical distance between the top of the ladder and the bottom of the ground is one leg, the horizontal distance between the bottom of the ladder and the building is another leg, and the length of the ladder is the hypotenuse.

For any right triangle, the Pythagorean Theorem states that the sum of the squares of both legs is equal to the hypotenuse squared ([tex]a^2+b^2=c^2[/tex]), where [tex]c[/tex] is the hypotenuse.

Let the length of the ladder be [tex]\ell[/tex] (hypotenuse of right triangle). The distance between the top of the ladder and the ground (vertical distance) can be represented as [tex]\ell -1[/tex].

From the Pythagorean Theorem, we then have:

[tex]7^2+(\ell-1)^2=\ell^2[/tex]

Expand using [tex](a-b)^2=a^2-2ab+b^2[/tex]:

[tex]49+\ell^2-2\ell+1=\ell^2[/tex]

Subtract [tex]\ell[/tex] from both sides and add [tex]2\ell[/tex] to both sides:

[tex]49+1=2\ell[/tex]

Combine like terms:

[tex]50=2\ell, \\2\ell =50[/tex]

Divide both sides by 2:

[tex]\ell=\frac{50}{2}=\boxed{25\text{ feet}}[/tex]

Therefore, the length of the ladder is 25 feet.

A golf ball is hit from ground level. Its path is modelled by the relation h(t) = -4.9 t2 + 27.2t , where h is the ball’s height above the ground, in meters, and t is the time, in seconds. Determine the time the ball is in the air.

Answers

Well its in the air any time marked on the parabola but assuming that time is the difference between the two x intercepts it would be 5.551 seconds. (Sorry im not 100 percent sure what it means)

I am need help and an explanation on how to read these graphs.

Answers

Answer:

i think its b

Step-by-step explanation:

The store employee works 35 hours per week. Which inequality can be used to find the dollar value, x, of weekly sales that the employee must make to earn more than $400 per week?

Answers

The store employee works 35 hours per week. Which inequality can be used to find the dollar value, x, of weekly sales that the employee must make to earn more than $400 per week?

a baceball team won 11 on its first 18 games at this rate how many games will the team win in a 162 game season

Answers

Answer:

Step-by-step explanation:

Set up the following proportion. x is the number of games you should win.

11/18 = x / 162  

11*162 / 18 = x

x = 99            You likely would be out of the playoffs with a number like this.

In sunlight, a vertical yardstick casts a 1 ft shadow at the same time that a nearby tree casts a 15 ft shadow. How tall is the tree? (Make a sketch to help solve the problem. Hint: 3ft equals one yard.)
A) 45 ft
B) 50 ft
C) 44 ft
D) 48 ft

Answers

Answer: A) 45 ft

Step-by-step

The yardstick is 3ft tall since 1 yard = 3ft. It is 3 times as tall as its shadow. The tree has a 15ft long shadow. The tree should also be 3 times as tall as its shadow. The tree is 15*3ft tall, so it is 45ft tall. I attached an image of the diagram I made.

Given C(4, 3) and D(-4, -3) are two points on a circle, centered at the origin. Given
that CD is a diameter of the circle?

a) Find the radius of the circle.

b) State the equation of the circle

Answers

Given C(4, 3) and D(-4, -3) are two points on a circle, centered at the origin. Given
that CD is a diameter of the circle?

a) Find the radius of the circle.

If there is a song that is 2 minutes and 58 seconds long and it plays 40 times how long does it play convert answer into seconds.

Answers

Answer: I got 7120 seconds

Step-by-step explanation:

There's 178 seconds in the song (for more context, I just converted the 2 minutes into seconds and added it with 58) then I multiplied it by the total amount of times it played (in this case, 40)

Hope this helps

A ship sailed 30 kilometers in 1 1/2 hours. What is was its rate in kilometers per hour?
1) 20
2)30
3)45
4)90
5)Not enough information is given.

Answers

Answer:

20km/hr

Step-by-step explanation:

Given that a ship sailed 30km in one and a half hours. We need to find out the rate of ship in kilometres/hour . The rate is also called Speed.

Speed:- Distance travelled per unit time is called Speed .

Here , according to Question,

Distance = 30 km

Time = 1½ hrs .

We know that ,

[tex]\rm\implies Distance = Speed \times Time [/tex]

Subsequently ,

[tex]\rm\implies Time = \dfrac{Distance}{Time} [/tex]

Substitute the respective values ,

[tex]\rm\implies Rate =\dfrac{ 30km}{ 1.5 hrs } [/tex]

We can write 1.5 as 3/2 , therefore ,

[tex]\rm\implies Rate = \dfrac{ 2\times 30}{3} km/hr[/tex]

Simplify the RHS ,

[tex]\rm\implies\boxed{\blue{\rm Rate = 20\ km/hr}} [/tex]

Hence the Rate/Speed of the ship is 20km/hr .

in the given figure poq is a line. if x=30 then find qor and ros​

Answers

Answer:

[tex]2y + 3y + x = 180 \\ 5y + 30 = 180 \\ 5y = 180 - 30 \\ 5y = 150 \\ y = 30[/tex]

QOR =3Y

=3×30

=90°

ROS = 2Y

=2×30

=60°

help I was never taught how to do this im confused

Answers

Answer:

36

Step-by-step explanation:

Area of a triangle = (bh)/2

Where b = base length and h = height

Given base length: 18ft

Given height: 4ft

This being known let's define the variables

b = 18

h = 4

Now to find the area we simply plug in these values into the formula

Area = (18)(4)/2

Simplify multiplication 18 * 4 = 72

Area = 72/2

Simplify division

Area = 36

¿COMO PUTAS SE HACE i¹⁰⁰²?

Answers

Answer:

nose

Step-by-step explanation:

The ________ and variance are derived from a subset of the population data and are used to make inferences about the population.
a. population standard deviation.
b. population variance.
c. population mean.
d. sample mean.

Answers

Answer:

the answer is option A population standard deviation

The temperature on a cold winter day starts out at 10 degrees, but it drops rapidly 24 degrees due to a strong cold front moving in. What is the current temperature?

Answers

-34 degrees (10-24=-34)

Plz help me find zero x on the triangle and show work thanks​

Answers

Answer:

x= 30 degrees

Step-by-step explanation:

This is an isosceles triangle as indicates by the lines on the sides.

Since the sides lengths are equal, the base angles are  equal

x= 30 degrees

Which set of angles listed are supplementary

Answers

Answer:

A. <BED and <DEA, <AEC and <BEC

Step-by-step explanation:

Supplementary angles add up to give 180°.

m<BED = 90°

m<DEA = 90°

m<BED + m<DEA = 180°

Therefore, <BED and <DEA are supplementary.

m<AEC = 90°

m<BEC = 90°

m<AEC + m<BEC = 180°

Therefore, <AEC and <BEC are supplementary.

An integer is 18 more than 4 times another. If the product of the two integers is -18, then find the integers.

Answers

Answer:

Step-by-step explanation:

x = 4y+18

xy = -18

x = -18/y

-18/y = 4y+18

4y² + 18y + 18 = 0

2y² + 9y + 9 = 0

y = [-9 ±√(9²-4(2)(9))]/[2(2)] = [-9 ± 3]/4 = -1.5, -3

-1.5 is an extraneous solution, so y = -3

x = 6

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