Answers
Answer:
It’s E
Step-by-step explanation:
The length of the diagonal of the figure considered is given by: Option E: 5√2
What is Pythagoras Theorem?If ABC is a triangle with AC as the hypotenuse and angle B with 90 degrees then we have:
[tex]|AC|^2 = |AB|^2 + |BC|^2[/tex]
where |AB| = length of line segment AB. (AB and BC are rest of the two sides of that triangle ABC, AC being the hypotenuse).
Consider the figure attached below.
The triangle ABC is a right angled triangle as one of its angle is of 90 degrees.
Thus, we can use Pythagoras theorem here to find the length of the diagonal line AC.
Since it is given that:
|AB| = 5 units = |BC|, thus, we get:
[tex]|AC|^2 = |AB|^2 + |BC|^2\\\\|AC| = \sqrt{5^2 + 5^2} = \sqrt{2 \times 5^2} = \sqrt{5^2} \times \sqrt{2} = 5\sqrt{2} \: \rm units[/tex]
We didn't took negative of root as length cannot be negative.
Thus, the length of the diagonal of the figure considered is given by: Option E: 5√2
Learn more about Pythagoras theorem here:
https://brainly.com/question/12105522
Related Questions
Determine the center and radius of the circle described by the question.
(X+2)
Answers
The question is incomplete, I will however explain, with an illustration, how to determine the center and radius of a circle.
Step-by-step explanation:
The standard equation of a circle is given as:
(x - a)² + (y - b)² = r² ........................(1)
Where (a, b) is the center of the circle, and r is the radius.
An expression can be given for us to find the center and the radius of the circle.
Suppose we were given the expression:
x² + y² - 10x + 4y - 7 = 0.....................(2)
To find the center and the radius, it is left for us to rewrite (2) in the form of (1).
Rearranging (2), we have
(x² - 10x) + (y² + 4y) = 7
Completing the squares of each bracket
(x² - 10x + 25 - 25) + (y² + 4y + 4 - 4) = 7
(x² - 10x + 25) + (y² + 4y + 4) - 25 - 4 = 7
(x² - 10x + 25) + (y² + 4y + 4) - 29 = 7
(x - 5)² + (y + 2)² = 7 + 29
(x - 5)² + (y + 2)² = 36
Or
(x - 5)² + (y + 2)² = 6² .....................(3)
Comparing (3) with one, we see that
a = 5, b = -2, and r = 6
Therefore it is a circle centered at (5, -2) with a 6 unit radius.
A circle is defined by the equation given below.
x^2+y^2-x-2y-11/4=0
What are the coordinates for the center of the circle and the length of the radius?
Answers
Answer:
(1/2, 1)
2
Step-by-step explanation:
x² + y² − x − 2y − 11/4 = 0
x² − x + y² − 2y = 11/4
Complete the squares.
x² − x + 1/4 + y² − 2y + 1 = 11/4 + 1/4 + 1
(x − 1/2)² + (y − 1)² = 4
The center of the circle is (1/2, 1) and the radius of the circle is 2.
Answer:
Option A
Step-by-step explanation:
[tex](\frac{1}2} ,1)[/tex], 2 units
Determine the least number of patties that will share equally among groups og 6, 9, 12
Answers
Answer:
72.
Step-by-step explanation:
Given a group of 6, 9 and 12.
We are to determine the least number of patties that will be shared equally among the groups.
This we do by determine the Least common multiple of the three numbers.
[tex]6=2 X 3\\9 = 3 X 3\\12 =2 X 2 X 2\\L.C.M.=2^3X3^2=72[/tex]
Therefore, the least number of patties that can be shares equally among groups of 6, 9 and 12 is 72.
Indigo Depot is having a clearance sale of their summer items. A swimsuit that originally cost $120 before any discount is on sale for 15% off. If the swimsuit is then put on clearance for an additional 40% off the sale price, what is the final price? Round your answer to the nearest cent, if necessary.
Answers
Answer:
20
Step-by-step explanation:
Answer:
$61.20
Step-by-step explanation:
15% sale:
$120 - 15%= $120*0.85= $10240% sale:
$102 - 40%= $102*0.6= $61.20State if each scenario involves a permutation or a combination. Then find the number of possibilities.
The batting order for seven players on a 8 person team.
a)Permutations: 120.960
b)Combinations: 20,160
c)Permutations: 40320
d)Combinations: 8
Answers
Answer:
c) Permutations: 40320
Step-by-step explanation:
We have that permutations are groupings in which the order of the objects matters. Combinations are groupings where content matters but order does not.
In this case, then the batting order, therefore the order does matter, therefore, it would be a permutation, where n = 8 and r = 7
nPr = n! / (n-r)!
Replacing:
8P7 = 8! / (8-7)! = 40320
Which means that the answer is c) Permutations: 40320
You are renting a car that charges a $30 fee plus 40 cents a mile. The rate of change
is $30.
True
False
Answers
Answer:
true
is the answer
Find the factorization of the polynomial below.
81x2 - 18x + 1
Answers
Answer:
(9x - 1)²
Step-by-step explanation:
If you can tell, the square root of 81 is 9. This should be a clue that the polynomial could be one binomial squared. If you tried factoring starting out with 9x in both parenthesis, you could see that you would get (9x - 1)² as your answer.
Answer:
(9x-1)²
Step-by-step explanation:
81x² - 18x + 1= (9x)²- 2*9x+1²= (9x-1)²
A blueprint of a new house has a scale of 1inch 5 feet The length of the family room on the family room on the drawing is 4/4 inches. How long is the family room
Answers
Answer:87
Step-by-step explanation:
866
A publisher reports that 41% of their readers own a laptop. A marketing executive wants to test the claim that the percentage is actually less than the reported percentage. A random sample of 320 found that 36% of the readers owned a laptop. Is there sufficient evidence at the 0.05 level to support the executive's claim? Find the value of the test statistic. Round your answer to two decimal places. Specify if the test is one-tailed or two-tailed. Determine the decision rule for rejecting the null hypothesis, H0. Make the decision to reject or fail to reject the null hypothesis. State the conclusion of the hypothesis test.
Step 1 of 6: State the null and alternative hypotheses.
Answers
Answer:
Step-by-step explanation:
Hello!
The objective is to test the claim that less than 41% of the publisher's readers own a laptop.
To do so, a sample of 320 readers was taken and the proportion of readers that own a laptop resulted in 36%
Be X: number of readers that own a laptop.
X~Bi(n;p)
n=320
Sample proportion p'= 0.36
The hypotheses are:
H₀: p ≥ 0.41
H₁: p < 0.41
α: 0.05
[tex]Z=\frac{p'-p}{\sqrt{\frac{p(1-p)}{n} } }[/tex]≈N(0;1)
[tex]Z_{H_0}=\frac{0.36-0.41}{\sqrt{\frac{0.41(1-0.41)}{320} } }= -1.82[/tex]
This test is one-tailed to the left, meaning, that you'll reject the null hypothesis to small values of Z, there is only one critical value that defined the rejection region:
[tex]Z_{\alpha }= Z_{0.05}= -1.645[/tex]
The decision rule is:
If [tex]Z_{H_0}[/tex] ≤ -1.645, reject the null hypothesis.
If [tex]Z_{H_0}[/tex] > -1.645, do not reject the null hypothesis.
The calculated value is less than the critical value, then the decision is to reject the null hypothesis.
So at a 5% significance level, the test is significant. You can conclude that the population proportion of the publisher's readers that own a laptop is less than 41%.
I hope this helps!
There are 11 apples in a basket. 9 of these apples are green. The rest of them are red. What is the ratio of red apples to all apples in the basket? What is the ratio of red apples to green apples?
Answers
Answer:
Red apples to all apples =2/11
Red apples to green apples =2/9
Step-by-step explanation:
There are 11 total apples 9 of them are green and the rest are red so there are 11-9=2 red apples
The ratio of red apples to all apples = number of red apples ÷ total apples number = 2÷11
The ratio of red apples to green apples = number of red apples ÷ number of green apples = 2÷9
Answer:
Red apples to all apples =2/11
Red apples to green apples =2/9
Step-by-step explanation:
There are 11 total apples 9 of them are green and the rest are red so there are 11-9=2 red apples
The ratio of red apples to all apples = number of red apples ÷ total apples number = 2÷11
The ratio of red apples to green apples = number of red apples ÷ number of green apples = 2÷9
Step-by-step explanation:
Do consumers spend more on a trip to Target or Walmart? Suppose researchers interested in this question collected a systematic sample for 84 Target customers and 80 Walmart customers by asking customers for their purchase amount as they left the store. Using the given summary statistics, researchers calculated a 95% confidence interval for the mean difference between Target and Walmart purchase amounts. The interval was ($negative 15.05,$negative 2.95). Explain in context what this interval means.
Answers
Answer:
Step-by-step explanation:
Confidence interval for the difference between two population means is written in the form,
difference in sample means ± margin of error
The difference in sample means is the point estimate for the difference in population means. In the given scenario, the point estimate is the difference in mean amount spent by the sampled customers on a trip to Target or Walmart.
Since the interval was (- $15.05,$2.95), it means that the lower limit is - $15.05 and the upper limit us $2.95.
Therefore, the 95% confidence interval is providing a range that we are 95% confident that the true difference in mean amount spent by Target customers and Walmart customers falls between - $15.05 and $2.95
laura quiere cúbrir con papel de china una puerta como la que se muestran el dibujo cuánto centímetros cuadrados es la que tendra que cubrir con papel de china
Answers
Answer:
Necesita cubrir 4800 cm^2.
Step-by-step explanation:
La pregunta está incompleta:
Laura quiere cubrir con papel de china una puerta como la que se muestra en el dibujo. Las medidas son 80 cm de largo y 60 cm de ancho.
Tenemos que calcular la superficie de la puerta, cuyas medidas son 80 cm de largo y 60 cm de ancho.
Para calcular el área simplemente multiplicamos las medidas de ambos lados:
[tex]A=80\,cm\cdot 60\,cm=4800\,cm^2[/tex]
One week 72 people got a speeding ticket the next week only 36 people get a speeding ticket what is the percentage of change in the speeding tickets
Answers
Answer:
The answer would be 50%
Step-by-step explanation:
You Would get this by dviding 36/72 which would give you .5 and then you convert that to a percentage
Answer:
50%
Step-by-step explanation:
Suppose an All Greens store in Sonoma, California, wants to estimate a range of advertising costs appropriate to its store. If it spends too little on advertising, it will not reach enough customers. However, it does not want to overspend on advertising for this type and size of store. At this store, x1 = 163, x2 = 2.4, x3 = 188, x5 = 6.6, and x6 = 10. Use these data to predict x4 (advertising costs) and find an 80% confidence interval for your prediction. (Use 2 decimal places.)
Answers
Answer:
The advertising cost, X₄ = 5.626 million
The 80% confidence limits for X₄ is (5.041 , 6.100)
The 80% prediction limits for X₄ is (4.048 , 7.094)
Step-by-step explanation:
Using MINITAB
The regression equation is X₄ = 4.14 + 0.0431 X₁ - 0.800 X₂ + 0.00059 X₃ - 0.661 X₅ + 0.057 X₆
Predictor Coef SE Coef T P
Constant 4.142 1.626 2.55 0.019
X₁ 0.043089 0.009466 4.55 0.000
X₂ -0.7998 0.2515 -3.18 0.005
X₃ 0.000590 0.004221 0.14 0.890
X₅ -0.6606 0.1542 -4.28 0.000
X₆ 0.0574 0.1254 0.46 0.652
S = 1.07911 R-Sq = 93.4% R-Sq(adj) = 91.8%
Analysis of Variance
Source DF SS MS F P
Regression 5 345.966 69.193 59.42 0.000
Residual Error 21 24.454 1.164
Total 26 370.420
Source DF Seq SS
X₁ 1 309.464
X₂ 1 8.699
X₃ 1 5.994
X₅ 1 21.566
X₆ 1 0.244
Unusual Observation
Obs X₁ X₄ Fit SE Fit Residual St Resid
17 398 5.500 7.714 0.641 -2.214 -2.55 R
27 400 7.000 7.366 1.025 -0.336 -1.00 X
Where R is observation with a large standardized residual.
Where X is observation whose X values give it large influence.
Predicted values for new Observations
New
Obs Fit SE Fit 80% Cl 80% Pl
1 5.571 0.400 (5.041 , 6.100) (4.048 , 7.094)
Values of Predictors for New Observations
New
Obs X₁ X₂ X₃ X₅ X₆
1 163 2.40 188 6.60 10.0
∴ The advertising cost, X₄ = 5.626 million, The 80% confidence limits for X₄ is (5.041 , 6.100), and The 80% prediction limits for X₄ is (4.048 , 7.094)
How much money does the average professional hockey fan spend on food at a single hockey game? That question was posed to 10 randomly selected hockey fans. The sampled results show that sample mean and standard deviation were $ 18.00 and $ 2.75, respectively. Use this information to create a 90% confidence interval for the mean. Express the answer in the form x overbar plus or minus t Subscript alpha divided by 2 Baseline (s divided by StartRoot n EndRoot ).
Answers
Answer:
Now we have everything in order to replace into formula (1):
[tex]18-2.262\frac{2.75}{\sqrt{10}}=16.03[/tex]
[tex]18+2.262\frac{2.75}{\sqrt{10}}=19.97[/tex]
Step-by-step explanation:
Information given
[tex]\bar X=18[/tex] represent the sample mean
[tex]\mu[/tex] population mean (variable of interest)
s=2.75 represent the sample standard deviation
n=10 represent the sample size
Confidence interval
The confidence interval for the mean is given by the following formula:
[tex]\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}[/tex] (1)
The degrees of freedom are given by:
[tex]df=n-1=10-1=9[/tex]
The Confidence is 0.90 or 90%, the significance is [tex]\alpha=0.1[/tex] and [tex]\alpha/2 =0.05[/tex], and the critical vaue would be [tex]t_{\alpha/2}=2.262[/tex]
Now we have everything in order to replace into formula (1):
[tex]18-2.262\frac{2.75}{\sqrt{10}}=16.03[/tex]
[tex]18+2.262\frac{2.75}{\sqrt{10}}=19.97[/tex]
if AB = 3, AD= 5, andDE= 6, what is the length of BC?
Answers
Answer:
D. 3.6
Step-by-step explanation:
=> Taking proportionality of the similar sides to find BC
[tex]\frac{AB}{AD}=\frac{BC}{DE}[/tex]
[tex]\frac{3}{5} = \frac{BC}{6}[/tex]
Multiplying 6 to both sides
[tex]BC = 0.6 * 6[/tex]
BC = 3.6
plsss help meeeeeee I would really appreciate it I would be really happy if u help meeee
Answers
[tex]the \: answer \: is \: 22.4 \: cm \\ please \: see \: the \: attached \: picture \\ for \: full \: solution \\ hope \: it \: helps[/tex]
The length of AE is 22.4cm rounded to one decimal place.
Select the correct answer from each drop-down menu. A quadrilateral has vertices A(11, -7), B(9, -4), C(11, -1), and D(13, -4). Quadrilateral ABCD is a . If the vertex C(11, -1) were shifted to the point C′(11, 1), quadrilateral ABC′D would be a .
Answers
Answer:
Quadrilateral ABCD is a Quadrilateral with four equal sides so either a rhombus or square
But
Quadrilateral ABC'D is a quadrilateral with two adjacent sides equal so it's a kite shape
Step-by-step explanation:
(11, -7), B(9, -4), C(11, -1), and D(13, -4).
Let's take out the values of x and y coordinate with the way they are arranged
X = 11,9,11,13
Y = -7,-4,-1,-4
So we observe that distance of the coordinates on either x is 2 units and y is 3 units.
But when the the value was changed to
C′(11, 1), (11, -7), B(9, -4), C′(11, 1), and D(13, -4).
There was difference of 2 unit and 4 unit making the new shape a kite.
The diagram attached explain better
Answer:
1. rhombus with non-perpendicular adjacent sides
2. kite
Step-by-step explanation:
i just got it right on edmentum.
Please mark as brainliest.
A country commits to decreasing spending for infrastructure in various ways at a rate of 30% per year. At the time of the announcement, the country is spending $12 billion per year. Which graph models the amount of infrastructure spending for future years?
Answers
Answer:
You want the curve to be decreasing from left to right since they are decreasing the amount spent so we can eliminate options 2 and 3. The initial amount (when x = 0) has to be 12 so the answer is the last option.
The average retirement age for a certain country was reported to be 56.4 years according to an international group dedicated to promoting trade and economic growth. With the pension system operating with a deficit, a bill was introduced by the government during the summer to raise the minimum retirement age from 60 to 62. Suppose a survey of 40 retiring citizens is taken to investigate whether the new bill has raised the average age at which people actually retire. Assume the standard deviation of the retirement age is 55 years. Using α=0.10
Required:
Calculate the probability of a Type II error occurring if the actual population age is 57.5 years old.
Answers
Answer:
|Z| = |-0.126| = 0.126 < 1.645
Null hypothesis is accepted
The retiring citizens is taken to investigate whether the new bill has raised the average age at which people actually retire.
μ = 57.5
Step-by-step explanation:
Explanation:-
The average retirement age for a certain country was reported to be 56.4 years
The mean of the sample x⁻ = 56.4
The standard deviation of the Population 'σ'= 55 years
The mean of the population μ = 57.5
Null hypothesis: H₀:The retiring citizens is taken to investigate whether the new bill has raised the average age at which people actually retire.
μ = 57.5
Alternative Hypothesis : H₁: μ ≠57.5
Test statistic
[tex]Z = \frac{x^{-}-mean }{\frac{S.D}{\sqrt{n} } }[/tex]
critical value:
[tex]Z_{\frac{\alpha }{2} } = Z_{0.05} =1.645[/tex]
[tex]Z = \frac{56.4-57.5 }{\frac{55}{\sqrt{40} } } = -0.126[/tex]
|Z| = |-0.126| = 0.126 < 1.645
The null hypothesis is accepted
Conclusion:-
The retiring citizens is taken to investigate whether the new bill has raised the average age at which people actually retire.
μ = 57.5
The function f(x) = −x2 + 16x − 60 models the daily profit, in dollars, a shop makes for selling candles, where x is the number of candles sold. Determine the vertex, and explain what it means in the context of the problem. (6, 10); The vertex represents the maximum profit. (6, 10); The vertex represents the minimum profit. (8, 4); The vertex represents the minimum profit. (8, 4); The vertex represents the maximum profit.
Answers
Answer:
A.
f is a quadratic function, which means it's graph is a parabola.
Notice that the coefficient of is negative, so the parabola opens downwards.
the x-coordinate of a parabola is always determined by the formula:
where a is coefficient of the term, and b is the coefficient of the x term.
Thus, x-coordinate of the vertex of the graph of f is :
the y-coordinate of the vertex is f(8)=-8*8+16*8-60=4.
The vertex is (8, 4).
This means that the maximum daily profit is when exactly 8 candles are sold.
B.
The x-intercepts are the values of x such that f(x)=0,
so to find these values we solve:
complete the square:
so x-8=2 or x-8=-2
the roots are x=10 and x=6, are the roots.
This means that when the shop sells exactly 6 or 10 candles, it makes no profit.
Answer: d (8, 4); The vertex represents the maximum profit.
Explanation: i got it right on the test
Solve 5x - c = k for x.
Answers
Answer:
Step-by-step explanation:
5x - c = k
Add c to each side
5x - c+c = k+c
5x = (k+c)
Divide each side by 5
5x/5 = (k+c)/5
x = (k+c)/5
Answer:
x=(k+c)/5
Step-by-step explanation:
5x-c=k (Original Equation)
5x-c+c=k+c (Addition Property of Equality)
5x=k+c (Simplify)
x=(k+c)/5 (Division Property of Equality)
Two lines intersect and two of the vertical angles measure 37°. What is the measure of the other two vertical angles?
Answers
Answer:
286 degrees and 143 degrees
Step-by-step explanation:
When line intersect the two vertical angle adds up to 180 degrees
To find the other vertical angle:
180 -37=143 degrees
So for two vertical angles
we take (180*2)-(37*2)=286 degrees
A research firm regularly conducts customer satisfaction surveys for an amusement park. A survey of 100 randomly selected park visitors on a weekday in May concluded the average age of visitors to the park was 37 years. When the survey was repeated with 100 randomly selected park visitors on a Saturday in May the average age of visitors to the park was determined to be 17 years
a) What is the population of interest in this situation?
b) How many samples were described?
c) Is the average age of 37 years a parameter or a statistic?
d) Tell whether this information represents a quantitative or qualitative variable? - age of the visitor - whether the visitor has a season pass
e) What possible explanation is there for the large difference in age between the two samples?
Answers
Answer:
(a) The population of interest in this situation is the average age of visitors to the park in MAY during weekdays or weekends.
(b) Two samples are described in the above situation, that is;
A survey of 100 randomly selected park visitors on a weekday in May.A survey of 100 randomly selected park visitors on a Saturday in May.(c) The average age of 37 years is a statistic.
(d) The above information represents a quantitative variable.
(e) The possible explanation for the large difference in age between the two samples would be that during weekdays most of the teenagers or children below 20 years of age are not able to come to parks because of their schools, coachings or some studies related work.
Step-by-step explanation:
We are given that a research firm regularly conducts customer satisfaction surveys for an amusement park. A survey of 100 randomly selected park visitors on a weekday in May concluded the average age of visitors to the park was 37 years.
When the survey was repeated with 100 randomly selected park visitors on a Saturday in May the average age of visitors to the park was determined to be 17 years.
(a) The population of interest in this situation is the average age of visitors to the park in MAY during weekdays or weekends.
(b) Two samples are described in the above situation, that is;
A survey of 100 randomly selected park visitors on a weekday in May.A survey of 100 randomly selected park visitors on a Saturday in May.(c) The average age of 37 years is a statistic as it is the sample average age of visitors to the park on a weekday, i.e. [tex]\bar X_1[/tex] = 37 years.
(d) The above information represents a quantitative variable because in this we are concerned about the average age of visitors in the park which is a numeric value and we are not interested in any qualitative aspect.
(e) The possible explanation for the large difference in age between the two samples would be that during weekdays most of the teenagers or children below 20 years of age are not able to come to parks because of their schools, coachings or some studies related work.
But during weekends like Saturday, the schools or coaching institutions are generally closed due to which they are able to come to parks to play and because of this there are large number of children below 20 years of age who visit parks on weekends.
the correct
9. 5(x - 2) = 15
a. 10
b. 5
c. 1
Answers
Answer:
the answer is 5
Step-by-step explanation:
Answer:
x=5
Step-by-step explanation:
5x-10=15
5x=25
x=5
G(x) =19.60 + 1.75x what is the value of g (30) ?
Answers
Answer:
72.1
Step-by-step explanation:
G(x) =19.60 + 1.75x
Let x = 30
G(30) =19.60 + 1.75*30
=19.60 +52.5
72.1
graph the function f(x)=(x+2)(x-4). Which describes all of the values for which the graph is negative and decreasing?
Answers
Answer:
[tex]x\in(-2,1)[/tex]
Step-by-step explanation:
We are given that a function
[tex]f(x)=(x+2)(x-4)[/tex]
[tex]f(x)=x^2-2x-8[/tex]
Differentiate w.r.t x
[tex]f'(x)=2x-2[/tex]
[tex]f'(x)=0[/tex]
[tex]2x-2=0[/tex]
[tex]2x=2\implies x=\frac{2}{2}=1[/tex]
Therefore, intervals
[tex](-\infty,1),(1,\infty)[/tex]
Interval :[tex](-\infty,1)[/tex]
x=0
[tex]f'(0)=-2<0[/tex]
Decreasing function.
Interval:[tex](1,\infty)[/tex]
Substitute x=2
[tex]f'(2)=2(2)-2=2>0[/tex]
Function increasing.
From given graph we can see that function is negative for the values of x
-2<x<4
Hence, the graph is negative and decreasing for the values of x
[tex]x\in(-2,1)[/tex]
Answer:the answer is c/ all real values of x where 1<x<4
Step-by-step explanation:
edge 2020
Lisa reads 46 pages and Sunday 15 pages on Monday and 19 pages on Tuesday which of the following is the closest to the mean number of the pages she read over the three dayperiod
Answers
Answer:
80
Step-by-step explanation:
46+15+19 which should give you a total answer of 80
Which equation has two real solutions?
A. x2 = –100
B. 5x2 = 1
C. 6x2 + 17 = 11
D. 7(x2 + 6) = 42
Answers
Answer:
B. 5x² = 1Step-by-step explanation:
A. x² = –100
This equation has no solution because x² is always positive.
B. 5x² = 1
then x² = 1/5
then x = 1/(√5) or x = -1/(√5)
C. 6x² + 17 = 11
then 6x² = 11 - 17 = -6
then x² = -6/6 = -1
This equation has no solution because x² is always positive.
D. 7(x + 6) = 42
then x + 6 = 42/7 = 6
then x = 6 - 6 = 0
_____________________
:)
Sam colors each tile in a 4 by 4 grid white or black. A coloring is called rotationally
symmetric if the grid can be rotated 90, 180, or 270 degrees to achieve the same pattern.
Two colorings are called rotationally distinct if neither can be rotated to match the
other. How many rotationally distinct ways are there for Sam to color the grid such
that the colorings are not rotationally symmetric?
Answers
Answer:
65,280
Step-by-step explanation:
Consider the 4×4 grid ...
[tex]\left[\begin{array}{cc}a&b\\d&c\end{array}\right][/tex]
where each of a, b, c, d is a 2×2 array of tiles. Let's use the notation a' to represent the 2×2 array "a" rotated right 1/4 turn. For 90° rotational symmetry, we must have b=a', c=b'=a'', d=c'=b''=a'''. That is, once "a" is determined, the rest of the grid is determined. Since "a" consists of 4 tiles, each of which can be black or white, there are 2^4 = 16 patterns that have 90° rotational symmetry.
The same will be true of 270° rotational symmetry, for the same reason.
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For 180° rotational symmetry, we must have c=a'' and d=b''. Then the combination of "a" and "b" together fully determines the grid. Together, "a" and "b" consist of 8 tiles, so there are 2^8 = 256 ways to pattern the grid so it will have 180° rotational symmetry. (Of those, 16 have 90° symmetry, and 16 have 270° symmetry. The sets are overlapping.)
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The 16 tiles of the grid can be colored 2^16 = 65,536 different ways. As we have seen, 256 of those colorings result in 180° rotational symmetry. Then the number of colorings that have no rotational symmetry is ...
65,536 -256 = 65,280 . . . . colorings not rotationally symmetric