Prove that in n , a single point {} is a closed
sets
please write down your answer in detail.
To prove that a single point {a} is a closed set in Rⁿ, we need to show that its complement, denoted as Rⁿ \ {a}, is open.
Let's consider an arbitrary point x in the complement Rⁿ \ {a}. Since x is not equal to a, there exists a positive radius r such that the open ball B(x, r) centered at x with radius r does not contain a.
Now, let's show that B(x, r) is entirely contained within Rⁿ\ {a}. We need to demonstrate that for any point y in B(x, r), y is also in Rⁿ \ {a}.
If y is equal to x, then y is not equal to a since a is excluded from Rⁿ \ {a}. Therefore, y is in Rⁿ\ {a}.
If y is not equal to x, then we can consider the distance between y and a. Since y is in B(x, r), we have:
d(y, x) < r
However, since a is not in B(x, r), we have:
d(a, x) ≥ r
Now, let's consider the distance between y and a:
d(y, a) ≤ d(y, x) + d(x, a) < r + (d(a, x) - r) = d(a, x)
Since d(y, a) is strictly less than d(a, x), it follows that y is not equal to a. Therefore, y is in Rⁿ \ {a}.
This shows that for every point x in Rⁿ \ {a}, there exists an open ball B(x, r) that is entirely contained within Rⁿ \ {a}. Hence, Rⁿ\ {a} is open.
By the definition of a closed set, if the complement of a set is open, then the set itself is closed. Therefore, a single point {a} is a closed set in Rⁿ.
The question should be:
Prove that in Rⁿ , a single point {a} is a closed sets.please write your answer in detail
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Michelle counted 40 green cars and 20 silver cars in the parking lot. If
the number of green cars stays the same, how many more silver cars
would need to be added so the ratio of green cars to silver cars is 1 to 3?
Answer:
100 more silver cars
Step-by-step explanation:
Right now the ratio of silver cars to green cars is 20:40 or 1:2, but if you add a hundred more silvers cars the ratio would 120:40 or 3:1.
20 Points!!! Pls help me out with this, and please no links.
Answer:
7
Step-by-step explanation:
Answer: your answer is B
Step-by-step explanation:
Im so sorry if im wrong, have a good day!
Find the radius of convergence, R, of the series. Σ (-7) Vn 00 ya n=1 R= Find the interval, I, of convergence of the series.
The series converges for x values within the interval (-29/7, -27/7), and the radius of convergence is 1/7.
How do we calculate?We apply the ratio test to our series:[tex]|7^(^n^+^1^)[/tex] (x + 4)[tex]^(^n^+^1^)^) / √(n+1)] / [( (x +7^n 4))^n\sqrtn]|[/tex]
We take the limit as n approaches infinity:lim(n→∞) |[tex]7(x + 4) / √(n+1)| = |7(x + 4)|[/tex]
For the series to converge, |7(x + 4)| must be less than [tex]1.|7(x + 4)| < 1-1 < 7(x + 4) < 1-1/7 < x + 4 < 1/7-29/7 < x < -27/7[/tex]
In conclusion, the interval of convergence is (-29/7, -27/7), and the radius of convergence is the half-length of the interval, which is 1/7.
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can someone answer this one too?
Answer:
1
Step-by-step explanation:
put x = 3
8(1/2³) = 8/8 = 1
What is the slope of the line through the points (-2, -1) and (4, 3)?
2/3
2/5
5/2
Answer:
The slope is A. 2/3
HOPE THIS HELPS!!!!
For a new study conducted by a fitness magazine, 260 females were randomly selected. For each, the mean daily calorie consumption was calculated for a September-February period. A second sample of 300 females was chosen independently of the first. For each of them, the mean daily calorie consumption was calculated for a March-August period. During the September-February period, participants consumed a mean of 2387.1 calories daily with a standard deviation of 210. During the March-August period, participants consumed a mean of 2412.9 calories daily with a standard deviation of 267.5. The population standard deviations of daily calories consumed for females in the two periods can be estimated using the sample standard deviations, as the samples that were used to compute them were quite large. Construct a 90% confidence interval for μ1−μ2, the difference between the mean daily calorie consumption of μ1 females in September-February and the mean daily calorie consumption of μ2 females in March-August.
Carry your intermediate computations to at least three decimal places. Round your answers to at least two decimal places. (If necessary, consult a list of formulas.)
What is the lower limit of the 90% confidence interval?
What is the upper limit of the 90% confidence interval?
the lower limit of the 90% confidence interval is approximately -65.25, and the upper limit is approximately 13.65.
To construct a 90% confidence interval for the difference between the mean daily calorie consumption of females in September-February (μ₁) and the mean daily calorie consumption of females in March-August (μ₂), we can use the formula:
CI = ([tex]\bar{X_1}[/tex] - [tex]\bar{X_2}[/tex]) ± Z * √((s₁² / n₁) + (s₂² / n₂))
Where:
[tex]\bar{X_1}[/tex] and [tex]\bar{X_2}[/tex] are the sample means of calorie consumption for the two periods.
s₁ and s₂ are the sample standard deviations of calorie consumption for the two periods.
n₁ and n₂ are the sample sizes for the two periods.
Z is the z-score corresponding to the desired confidence level.
Given data:
[tex]\bar{X_1}[/tex] = 2387.1 (mean daily calorie consumption for September-February)
[tex]\bar{X_2}[/tex] = 2412.9 (mean daily calorie consumption for March-August)
s₁ = 210 (standard deviation for September-February)
s₂ = 267.5 (standard deviation for March-August)
n₁ = 260 (sample size for September-February)
n₂ = 300 (sample size for March-August)
Confidence level = 90%
First, we need to find the z-score corresponding to a 90% confidence level. The z-score can be found using a z-table or a calculator. For a 90% confidence level, the z-score is approximately 1.645.
Now, we can substitute the values into the formula to calculate the confidence interval:
CI = (2387.1 - 2412.9) ± 1.645 * √((210² / 260) + (267.5² / 300))
Calculating the values inside the square root:
√((210² / 260) + (267.5² / 300)) ≈ √(342.461538 + 238.083333) ≈ √(580.544872) ≈ 24.107
Substituting the values into the formula:
CI = -25.8 ± 1.645 * 24.107
Calculating the limits of the confidence interval:
Lower limit = -25.8 - 1.645 * 24.107 ≈ -65.246
Upper limit = -25.8 + 1.645 * 24.107 ≈ 13.646
Rounding the values to two decimal places:
Lower limit ≈ -65.25
Upper limit ≈ 13.65
Therefore, the lower limit of the 90% confidence interval is approximately -65.25, and the upper limit is approximately 13.65.
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Angela purchased a car using a simple interest loan. The loan had an interest rate of 5% and was for three years. Angela paid $450 in interest. The principal amount of the loan was for $
Answer:
$3000
Step-by-step explanation:
Given data
Rate=5%
Time=3 years
Simple interest= $450
We know that the expression for simple interest is
SI=PRT/100
Substitute
450=P*5*3/100
cross multiply
P*15= 45000
Divide both sides by 15
P= 45000/15
P=$3000
Hence the principal amount is $3000
The equation below has infinitely many solutions.
-3 (x – 3) – 1 = ax + b
True
False
Answer:
False
Step-by-step explanation:
A. 3
B. 10
C. 20
D. 30
Answer:
D. 30Explanation:
292/100×9.9 = 2.92×9.9 = 28.908
30 is closest to 28.908
Give the similarity ratio for the following figures (small to large).
Answer: I think the answer would be 1/6
Step-by-step explanation:
If you notice, all of the numbers on the left model are 1/6 less than the one on the left. I don't know what type of answer they are looking for but the one on the left is 1.6 smaller than the one on the right:)
A variable needs to be eliminated to solve the system of equations below. Choose the
correct first step
— 5х + бу = 41
7x - 6y = -43
Answer:
6y-6y, cancel it out to find x first.
-5x+6y=41
7x-6y=-43
2x=-2
Step-by-step explanation:
i hope this helps :)
Answer:
Step-by-step explanation:
The first step is to add the 2 equations This will eliminate the y terms
( + 6y + -6y = 0).
So you are then left with 2x = -2
Please help me with the question
Answer:
the tree is 8ft long
Step-by-step explanation:
beans
SQUARE ROOT OF 21316 WITH STEP BY STEP SOLUTION THANKS
Answer:
146
Step-by-step explanation:
[tex] = \sqrt{21316 } [/tex]
[tex] = \sqrt{4 \times 5329} [/tex]
[tex] = 2 \sqrt{5329} [/tex]
[tex] = 2 \sqrt{73 \times 73} [/tex]
[tex] = 2 \times 73[/tex]
[tex] = 146[/tex]
A recent Gallup poll found large differences in the type of household chores done by wives and husbands.1 Wives still do most of the indoor household chores. Husbands still tend to do more work outside and with family cars. The simulated data in this problem are based on the results of this poll.
Suppose we wish to demonstrate that there is a difference between the proportions of wives and husbands who do laundry at home. From a random sample of 66 randomly selected wives, we observe 44 who do laundry at home. From a random sample of 46 husbands, we observe 18 who do laundry at home.
Test the claim that the proportion of wives, p1 , who do laundry at home is different from the proportion of husbands, p2 , who do laundry at home. Use a 1% significance level.
Answer : There is enough evidence to suggest that a higher proportion of wives do laundry at home compared to the proportion of husbands who do laundry at home.
Explanation:
The null hypothesis is that the proportion of wives and husbands who do laundry at home is the same. The alternative hypothesis is that the proportion of wives and husbands who do laundry at home is different.
Mathematically, null and alternative hypotheses are given below. H0: P1 - P2 = 0H1: P1 - P2 ≠ 0 where P1 is the proportion of wives who do laundry at home and P2 is the proportion of husbands who do laundry at home. Let α = 0.01 be the significance level. Therefore, α/2 = 0.005 and the Zα/2 value for the two-tailed test is ±2.58.
The point estimate of the difference in the proportions is:Point estimate, PE = P1 - P2 = (44/66) - (18/46) = 0.6667 - 0.3913 = 0.2754
The standard error of the difference in the proportions is: SE = sqrt{(P1(1 - P1)/n1) + (P2(1 - P2)/n2)} = sqrt{[(44/66)(22/66)/65] + [(18/46)(28/46)/45]} = 0.1033
The test statistic is given by:Z = (PE - 0) / SE = 0.2754 / 0.1033 = 2.6641
Since the absolute value of the test statistic is greater than the Zα/2 value, we reject the null hypothesis and conclude that the proportion of wives who do laundry at home is different from the proportion of husbands who do laundry at home at a 1% significance level. Therefore, there is enough evidence to suggest that a higher proportion of wives do laundry at home compared to the proportion of husbands who do laundry at home.
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use the law of cosines to find the missing angle. find m∠a to the nearest tenth of a degree
The law of cosines can be used to find the missing angle when the lengths of three sides of a triangle are known. In this case, we want to find the measure of angle a, so we'll use the formula: cos(a) = (b² + c² - a²) / (2bc)where a is the side opposite angle a, b is the side opposite angle b, and c is the side opposite angle c.
To find angle a, we need to rearrange the formula: cos(a) = (b² + c² - a²) / (2bc)cos(a) = (7² + 13² - 10²) / (2 * 7 * 13)cos(a) = 0.81923077a = cos⁻¹(0.81923077)a ≈ 34.2°Therefore, m∠a is approximately 34.2 degrees.
When either the lengths of the two sides and the measure of the included angle (SAS) or the lengths of the three sides (SSS) are known, the Law of Cosines is used to determine the remaining parts of an oblique (non-right) triangle.
The square of a side of an oblique triangle is equal to the sum of the squares of the other two sides minus twice the product of the two sides if A, B, and C are the measures of the angles of the triangle and a, b, and c are the lengths of the sides opposite the corresponding angles.
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Please help me I will mark...BRAINLIEST
I need volume and surface area
Answer:
1. V=60m³ SA=94m²
2. V=32m³ SA=88m²
3. V=2000mm³ SA=1000mm²
4. SA=376.8cm² V=552.64cm³
5. SA=1130.4cm² V=1356.48mm³
Step-by-step explanation:
1. Volume=5*4*3=60m³
Surface Area=2*(3*4)+2*(5*3)+2*(4*5)=24+30+40=94m²
2. Volume=8*4*1=32cm³
Surface Area=2*(8*1)+2*(8*4)+2*(4*1)=16+64+8=88cm²
3. Volume=10*10*20=2000mm³
Surface Area=2*(10*10)+2*(20*10)+2*(20*10)=200+400+400=1000mm²
4. SA of the cylinder=(2πr*h)+(2*πr²)=(2*(3.14)*4*11)+(2*3.14*16)
=(276.32)+(100.48)=376.8cm²
Volume=hπr²=11*(3.14)*16=552.64cm³
5. SA of cylinder=(2πr*h)+(2*πr²)=(2*(3.14)*12*3)+(2*3.14*144)
=(904.32)+(226.08)=1130.4mm²
Volume=hπr²=3*(3.14)*144=1356.48mm³
Number of participants = 274 Number of groups = 5 SSD = 1 SSW = 192 What is the mean squares within?
The mean squares within is 0.7130044843.
The formula to calculate the mean squares within is given below:
Mean squares within (MSW) = SSW / (n - k), where n = Total number of observations, k = Total number of groups.
Here, Number of participants = 274, Number of groups = 5, SSD = 1, SSW = 192.
Now, the value of n and k can be calculated using the formula given below:
n = Number of participants = 274, k = Number of groups = 5.
Let's substitute the values in the formula of mean squares within:
Mean squares within (MSW) = SSW / (n - k)
MSW = 192 / (274 - 5)
MSW = 192 / 269
MSW = 0.7130044843
Hence, the mean squares within is 0.7130044843.
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Los primeros días de enero, el representante del mercado recibió cierta cantidad de di-
nero, hizo una operación y se dio cuenta que habían pagado 15 personas. ¿Cómo puede
saber la cantidad recibida?
15
425
El ejercicio completo con las opciones de respuesta está a continuación:
Los primeros días de enero el representante del mercado recibió cierta cantidad de dinero,hizo una operación y se dio cuenta que habían pagado 15 personas,cómo puede saber la cantidad recibida?
a.Multiplicando el dividendo por el divisor
b. Sumando el dividendo con el cociente y el residuo
c.Multiplicando el divisor por el cociente y sumando el residuo
d.Multiplicando el dividendo por el cociente y sumando el residuo
Answer:
La opción c es la respuesta correcta
Step-by-step explanation:
El valor de 15 corresponde al cociente es decir al total de personas que pagaron;el ejercicio nos da el valor del divisor que es 425 ; para saber cual es la cantidad exacta recibida debemos multiplicar el divisor por el cociente y si hay residuo sumarlo; el ejercicio nos queda de la siguiente manera:
425 x 15 = 6.375 (la cantidad recibida fue de 6.375)
[tex]\frac{6375}{425}[/tex] = 15 (comprobación de la división para obtener el cociente con valor de 15)
Genoude towing test at the 0.10 vel tance by temperative contested to Put Assure at the comptes were obland de condendy ang simple random samping Test whether PPSample data are 30, 256, 38, 31 (a) Determine the rulanternative hypotheses. Choose the correct answer below OAH, versus H P = 0 OCH PD, versus HDD) OBH PP, VOUS HP) OD HIPP versus HDP (b) The fest statistics found to two decimal places as needed (c) The P values Round to three decimal places as needed) Test meil hypothesis. Choose the correct condusion below OA Roth null hypothesis because there is not suit evidence to conclude that, (b) The test statistic Zo is (Round to two decimal places as needed.) (c) The P-value is (Round to three decimal places as needed.) Test the null hypothesis. Choose the correct conclusion below. O A. Reject the null hypothesis because there is not sufficient evidence to conclude that p, p2. OC. Do not reject the null hypothesis because there is not sufficient evidence to conclude that p, #P2. OD. Reject the null hypothesis because there is sufficient evidence to conclude that p, p2.
The given problem involves hypothesis testing in statistics. The correct conclusion will depend on whether the null hypothesis is rejected or not.
(a) The null and alternative hypotheses can be determined as follows: OAH (One-sample test for proportion): P = 0 (H0) versus H P ≠ 0 (HA).
(b) The test statistic, denoted as Zo, needs to be computed using the given sample data.
(c) To determine the P-value, the calculated test statistic is compared to the appropriate distribution (e.g., standard normal distribution) based on the chosen significance level.
(d) Based on the P-value and the predetermined significance level, the null hypothesis is either rejected or not rejected. If the P-value is less than the significance level, the null hypothesis is rejected. Otherwise, the null hypothesis is not rejected.
The conclusion will depend on whether the null hypothesis is rejected or not and should be stated accordingly.
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If the unit rate is constant, what are the total sales for 12 pounds of asparagus?
PLEASE HELP ME OUT! QUICK POINTS FOR YOU!
All information needed can be found in the image below
Thank you in advance.
Answer:
3.14 units squared
Step-by-step explanation:
A = pi r^2
A = pi (1) ^2
A = pi = 3.14
(Radius = diameter / 2)
Evaluate (-2xy^3)^3 when x = 4 and y = -1
Step-by-step explanation:
(-2xy^3)^3
(-2(4)(-1)^3)^3
(-2(4)(-1))^3
(8)^3
512
mr. and mrs. simpson went to two movies. the first movie lasted 2 ⅓ hours and the second one lasted 1 ⅘ hours. how much longer was the first than the second movie?
The first movie was ⅔ hours longer than the second one.
The difference in length between the two movies, we need to subtract the length of the second movie from the first.
we need to convert the mixed numbers to improper fractions to make the subtraction easier.
2 ⅓ hours can be written as 7/3 hours.
1 ⅘ hours can be written as 8/5 hours.
Now, we can subtract them
7/3 - 8/5
we need a common denominator. The least common multiple of 3 and 5 is 15.
(7/3) * (5/5) - (8/5) * (3/3) = 35/15 - 24/15 = 11/15
Therefore, the first movie was 11/15 hours (or approximately 44 minutes) longer than the second one
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Please help Sammy buys light bulbs in pack of 8 for $20. The shipping cost is $10 regardless of the number of packs bought. Billy has only $120 to spend.
Answer:
5
Step-by-step explanation:
Arrange in ascending order 19,654 67,923 67,397 91,945
Answer:
19654,67397,67923,91945
Step-by-step explanation:
Ascending order mean arrange the number from smaller value to bigger value
Answer:
19654,67397,67923,91945
plz mark me as brainliest
A principal was buying T-shirts for his school's chess club and found that the total cost
in dollars could be found by the function f(x) = 9x + 19, where x is the number of
members in the club. If there are at least 8 members on the team but not more than
11, then which of the following statements describes the function?
A. The value of x must be a whole number between 8 and 11 and the value of f(x) must
be a whole number between 72 and 99.
B. The value of x must be a whole number between 8 and 11 and the value of f(x) must
be a whole number between 91 and 118.
C. The values of x and f(x) must both be whole numbers between 91 and 118.
D. The values of x and f(x) must both be whole numbers between 9 and 19.
evaluate each of the following
205 x 195
Answer:
39,975
Step-by-step explanation:
There u go
Answer:
39,975
Step-by-step explanation:
Caculater
Triangle ABC below has a right angle C and a height CD. (A height in a triangle connects its vertex and the opposite side, and is perpendicular to that side.)
If AC is 3 units long and BC is 4 units long, what is the length of AD?
can you show the picture please?
A cylindrical soup can has a diameter of 3 in. and is 6.2 in. tall. Find the volume of the can.
Answer:
b
Step-by-step explanation: