Given, an equivalence relation ~ on a set S. Let a and b be two elements in the set S. Assuming that [a] and [b] are two equivalence classes under the equivalence relation ~. Now we need to prove that either [a] = [b] or [a] ∩ [b] = ∅ (disjoint).
Proof:If [a] and [b] are not equal, then there must be some element c in the intersection of the equivalence classes [a] and [b]. i.e, c belongs to [a] and c belongs to [b].Thus, [a] ∩ [b] is not empty.
Let x be an element in [a], then x~a, and a~c (since c belongs to [a]) and hence x~c. So, x belongs to [c] which implies that [a] is a subset of [c].Now, let y be an element in [b], then y~b, and b~c (since c belongs to [b]) and hence y~c. So, y belongs to [c] which implies that [b] is a subset of [c].Thus, both [a] and [b] are subsets of [c].
Therefore, if [a] and [b] are not equal, then [a] and [b] are both subsets of [c] and hence the intersection of [a] and [b] is not empty. Thus, [a] and [b] are not disjoint. Hence, the proof by contradiction.
Conversely, if [a] and [b] are disjoint, then [a] ∩ [b] = ∅. And thus, [a] is not equal to [b].Therefore, two equivalence classes under the equivalence relation ~ are either equal or disjoint.
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9. What measure of central tendency is usually the preferred number by researchers for describing a group of scores?
10. Using the following data, calculate the standard deviation: 115, 125, 145, 150, 115, 125
The measure of central tendency that is usually the preferred number by researchers for describing a group of scores is the mean.
The measure of central tendency that is usually the preferred number by researchers for describing a group of scores is the mean. The mean provides the average score for a given set of data. It is calculated by summing up all the scores and dividing by the total number of scores. While other measures of central tendency, such as the median and mode, are also useful, the mean provides the most comprehensive picture of the data.
10. To calculate the standard deviation for the following data: 115, 125, 145, 150, 115, 125, you can use the following formula:
σ = √[(Σ(x - μ)²) / N]
Where:
σ = standard deviation
Σ = sum of
x = each score
μ = mean of all the scores
N = total number of scores
To find the standard deviation, first find the mean of the scores:
115 + 125 + 145 + 150 + 115 + 125 = 775
Total number of scores = 6
Mean = 775 / 6 = 129.17
Now, subtract the mean from each score, square the result, and add up all the squared differences:
(115 - 129.17)² + (125 - 129.17)² + (145 - 129.17)² + (150 - 129.17)² + (115 - 129.17)² + (125 - 129.17)² = 4666.79
Then, divide the sum of squared differences by the total number of scores and take the square root:
σ = √(4666.79 / 6) = 17.20
Mean = (115 + 125 + 145 + 150 + 115 + 125) / 6 = 129.17
Standard Deviation = √[ {(115 - 129.17)² + (125 - 129.17)² + (145 - 129.17)² + (150 - 129.17)² + (115 - 129.17)² + (125 - 129.17)² } / 6 ]
= √[4666.79 / 6]
= 17.20
Therefore, the standard deviation of the given data is 17.20.
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SOMEONE PLS HELP SHEHSJHSHS
Answer:
1. Quadrant II
2. Quadrant IV
3. Y-axis
Step-by-step explanation:
1. A package of sticky notes is in the shape of
a parallelogram. The dimensions of one
sticky note are shown. What is the area of
one sticky note?
A. 248.4 cm?
B. 124.2 cm2
C. 62.1 cm2
D. 22.7 cm2
Answer:
B. 124.2
Step-by-step explanation:
Area= b*h
Area= 13.5*9.2
Area = 124.2
Please Note* = Multiply
What is the volume of this sphere? Use a ~ 3.14 and round your answer to the nearest hundredth. 20 mm
Answer:
4186.67 cubic mm=V
Step-by-step explanation:
The volume of a sphere can be found using the equation, [tex]\frac{4}{3} \pi r^{3}[/tex]. It gives us the diameter but we need the radius. To find the radius just divde the diameter by 2, so the radius of the sphere is 10mm.
[tex]\frac{4}{3} (3.14) (10^{3})[/tex]=V
[tex]\frac{4}{3} (3.14) (1000)[/tex]=V
[tex]\frac{4}{3}[/tex](3140)=V
4186.67 cubic mm=V
The J.R. Simplot Company produces frozen French fries that are then sold to customers such as McDonald's. The "prime" line of fries has an average length of 6.00 inches with a standard deviation of 0.50 inch. To make sure that Simplot continues to meet the quality standard for "prime" fries, they plan to select a random sample of n = 100 fries each day. The quality analysts will compute the mean length for the sample. They want to establish limits on either side of the 6.00 inch mean so that the chance of the sample mean falling within the limits is 0.99. What should these limits be?
Answer:
(5.871 `; 6.127)
Step-by-step explanation:
Given :
Mean = 6
Standard deviation. σ = 0.5
Samplr size, n = 100
Zcritical at 99% confidence = 2.58
The confidence interval :
Mean ± margin of error
Margin of Error = Zcritical * σ / sqrt(n)
Margin of Error = 2.58 * 0.5/sqrt(100) = 0.129
Confidence interval :
Lower boundary = 6.00 - 0.129 = 5.871
Upper boundary = 6.00 + 0.129 = 6.129
(5.871 `; 6.127)
wayfktgfydfug9ugi0b7ffiobv57f9pogasdfyuiohfdfhjkl
Answer:
Area of the circle = 572.3 square ft.
Step-by-step explanation:
Area of a circle is given by the formula,
Area of a circle = πr²
Here 'r' = Radius of the circle
Diameter of circle given in the picture = 27 ft
Radius of the circle = [tex]\frac{27}{2}[/tex]
= 13.5 ft
Area of the circle = π(13.5)²
= 3.14(13.5)²
= 572.265
≈ 572.3 square ft
Please help.
Is algebra.
Answer:
1 is C
2 is B
3 is C
Step-by-step explanation:
Answer:
give em brainliest because i have no idea
Step-by-step explanation:
My Samsung charger broke so I went to Five Below to get a new one. They were on sale for $15,35 (not so five below). There
was a 6% tax too. How much did the new charger cost?
( I don’t need the explanation, only the right answer)
Answer:
The answer to your question is 16.27
Explanation:
You would start with the equation,
15.35 + 6% = C (Cost)
15.35 · 6% = 0.921
15.35 + 0.921 = 16.271
Round the one down, since it is less than four, and you get 16.27
Hope this helps.
waffletowne
7 ⅓ ÷ 225 =
answer this question plz
Answer:
0.03259..
Step-by-step explanation:
Prove the following:
(2cos x) / (cos 2x + 1) = sec x
The equation (2cos x) / (cos 2x + 1) = sec x is proven to be true.
We start with the expression on the left-hand side and simplify it step by step to show that it is equivalent to sec x.
(2cos x) / (cos 2x + 1) = (2cos x) / ((2cos^2 x - 1) + 1) [Using the double-angle formula cos 2x = 2cos^2 x - 1]
= (2cos x) / 2cos^2 x [Simplifying the numerator and denominator]
= cos x / cos^2 x [Cancelling out the factor of 2]
Now, we can simplify the expression further using the identity sec x = 1 / cos x:
cos x / cos^2 x = 1 / cos x = sec x.
Therefore, we have proved that (2cos x) / (cos 2x + 1) is equal to sec x.
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(q11) Find the center of mass of the system of objects that have masses 2 , 3 and 5 at the point (-1,2),(1,1) and (3,3) respectively.
The center of mass of the system of objects that have masses 2 , 3 and 5 at the point (-1,2),(1,1) and (3,3) respectively is located at the point (1.6, 2.2).
To find the center of mass of the system of objects, we need to consider the masses and positions of each object. Let's go through the steps to calculate the center of mass:
Assign variables to the masses and coordinates of the objects:
Object 1: Mass = 2, Coordinates = (-1, 2)
Object 2: Mass = 3, Coordinates = (1, 1)
Object 3: Mass = 5, Coordinates = (3, 3)
Calculate the total mass of the system by summing the masses of the objects:
Total mass = 2 + 3 + 5 = 10
Calculate the weighted average of the x-coordinates and y-coordinates to find the center of mass:
Center of mass (x-coordinate) = (m1 * x1 + m2 * x2 + m3 * x3) / Total mass
Center of mass (y-coordinate) = (m1 * y1 + m2 * y2 + m3 * y3) / Total mass
Substituting the values:
Center of mass (x-coordinate) = (2 * -1 + 3 * 1 + 5 * 3) / 10 = ( -2 + 3 + 15) / 10 = 16 / 10 = 1.6
Center of mass (y-coordinate) = (2 * 2 + 3 * 1 + 5 * 3) / 10 = (4 + 3 + 15) / 10 = 22 / 10 = 2.2
Therefore, the center of mass of the system of objects is located at the point (1.6, 2.2).
The center of mass represents the average position of the system, taking into account the masses and positions of the objects. It is a point where the system can be considered to be balanced. Calculating the center of mass is important in various areas of physics, such as studying the motion, stability, and collisions of objects.
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Which statement explains the type of function that is represented by the equation
y=x2 +9?
The volume of a square pyramid is 48 in^3 with a height of 4 inches. Find the length of one of the side of the base.
Answer:
6 inches
Step-by-step explanation:
area of square = 48 x 3 / 4 = 36 in^2
side = 6 in
Answer:
6 in
Step-by-step explanation:
The volume formula for a square-base pyramid of side length x and height h is V = (1/3)x²h. We want to solve this for the base side length x:
Multiplying both sides by (3/h) results in:
3V
----- = x² and so the side length, x, is √(3V/h).
h
Substituting 4 in for h and 48 in³ for V, we get: x = √(144 in³/4 in) = 6 in
Check: Does the volume formula given above result in 48 in³ when x = 6 in and h = 4 in?
V = (1/3)x²h = (1/3)(6 in)²(4 in) = 48 in³ YES: x = 6 in is correct.
Factor completely x3 − 2x2 − 8x + 16.
(x + 2)(x2 + 8)
(x − 2)(x2 + 8)
(x + 2)(x2 − 8)
(x − 2)(x2 − 8)
The expression x^3 - 2x^2 - 8x + 16 can be factored as (x - 2)(x^2 - 8).
To factor the given expression x^3 - 2x^2 - 8x + 16, we can look for common factors or factor it using grouping. In this case, we can observe that the expression can be factored by grouping.
First, we can factor out a common factor of (x - 2) from the first two terms:
x^3 - 2x^2 - 8x + 16 = (x - 2)(x^2 - 8x - 8)
Now, we can further factor the quadratic expression (x^2 - 8x - 8) by factoring out a common factor of 8:
(x^2 - 8x - 8) = (x - 2)(x - 8)
Therefore, the complete factorization of the expression x^3 - 2x^2 - 8x + 16 is:
(x - 2)(x - 2)(x - 8) which can also be written as (x - 2)(x^2 - 8).
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find the change-of-coordinates matrix from the basisB = {1-7t^2, -6 + t+43t^2, 1+6t} to the standard basis. Then write t^2 as a linear combination of the polynomials in B.
To find the change-of-coordinates matrix from basis B to the standard basis, we need to express the standard basis vectors as linear combinations of the vectors in B. Then, to write t^2 as a linear combination of the polynomials in B, we can use the change-of-coordinates matrix to transform t^2 into the coordinates with respect to B.
To find the change-of-coordinates matrix from basis B to the standard basis, we express the standard basis vectors as linear combinations of the vectors in B. Let's denote the standard basis vectors as e1, e2, and e3. We can write:
e1 = 1(1 - 7t^2) + 0(-6 + t + 43t^2) + 0(1 + 6t)
e2 = 0(1 - 7t^2) + 1(-6 + t + 43t^2) + 0(1 + 6t)
e3 = 0(1 - 7t^2) + 0(-6 + t + 43t^2) + 1(1 + 6t)
The coefficients in these equations give us the entries of the change-of-coordinates matrix.
To write t^2 as a linear combination of the polynomials in B, we can use the change-of-coordinates matrix. Let [t^2]_B represent the coordinates of t^2 with respect to B. Then, [t^2]_B = C[t^2]_std, where C is the change-of-coordinates matrix. We can solve this equation to find [t^2]_B.
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what are the values of a and b? a = 2y and b = 3 a = and b = –3y a = 2y and b = –3 a = and b = 3y
The values of a and b are dependent on the equation. For example, in the equation a = 2y and b = 3, then a = 6 and b = 3. However, in the equation a = 2y and b = -3, then a = -6 and b = -3.
In the given options, the values of a and b are stated as a = 2y and b = –3. This means that the value of a is equal to twice the value of y (a = 2y), and the value of b is equal to -3. The other options do not match these conditions. It is important to note that without further context or information about the variable y, we cannot determine a specific value for a or b. The values provided only establish the relationship between a, b, and y as described in the option a = 2y and b = –3.
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At 5 am, the temperature was -10°F. By noon the temperature was 7°F, What Integer
represents the change in temperature from 5 am, to noon?
Answer:
The integer that represents the change in temperature is 17.
Step-by-step explanation:
gh¯¯¯¯¯¯ has endpoints g(−3, 2) and h(3, −2). find the coordinates of the midpoint of gh¯¯¯¯¯¯ . a. (−3, 0) b. (0, 2) c. (0, 0) d. (0, −2)
The coordinates of the midpoint of the line segment GH with endpoints G(-3, 2) and H(3, -2) are (0, 0). The correct option is (C).
To determine the coordinates of the midpoint of the line segment GH with endpoints G(-3, 2) and H(3, -2), we can use the midpoint formula.
The midpoint formula states that the coordinates of the midpoint (M) are given by the average of the x-coordinates and the average of the y-coordinates of the endpoints.
Midpoint (M) = ((x1 + x2) / 2, (y1 + y2) / 2)
For GH, plugging in the coordinates, we have:
Midpoint (M) = ((-3 + 3) / 2, (2 + -2) / 2)
Midpoint (M) = (0, 0)
Therefore, the coordinates of the midpoint of GH are (0, 0), which corresponds to option c. (0, 0).
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what are the answers to a, b, c, d?
Answer:
Step-by-step explanation:
Determine the area and circumference of a circle with radius 12 cm.
The area of the circle is 452.16 cm², and the circumference is 75.36 cm.
To determine the area and circumference of a circle with a radius of 12 cm, we can use the formulas:
Area = π * r²
Circumference = 2 * π * r
The radius (r) is 12 cm, we can substitute this value into the formulas to find the area and circumference.
Area = π * (12 cm)²
= π * 144 cm²
≈ 3.14 * 144 cm²
≈ 452.16 cm²
The area of the circle is approximately 452.16 square centimeters.
Circumference = 2 * π * 12 cm
= 2 * 3.14 * 12 cm
≈ 75.36 cm
The circumference of the circle is approximately 75.36 centimeters.
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Write and solve an equation to find the missing dimension of the figure.
Answer:
15.5769230769
Step-by-step explanation:
8×13 = 104
1620÷104 = 15.5769230769
Find the area of the figure
Answer:
A=153.94
Step-by-step explanation:
A function, f(x),represents the height of a plant x months after being planted. Students measure and record the height on a
Select the appropriate domain for this situation.
OA.
the set of all real numbers
OB.
the set of all integers
O c.
the set of all positive integers
OD
the set of all positive real numbers
Answer:
I think the answer would be A or B, the best would be B.
Step-by-step explanation:
K so since it is monthly, it would not be all positive data. So you are left with A or B. Integers are numbers that are positive and negative so since the data can be a range of positive and negative numbers, that is why the data set of all integers (b) is the best choice.
Your welcome :D
Simplify the following expressions to have fewer terms (MIDDLE SCHOOL)
5x-3+(4x-6)+2
4y+3-(8x-2)
Answer:
Install math calculator
Thank you
Answer:
x=1\9
Step-by-step explanation:
first part:
5x-3+4x+2
5x+4x-3+2
9x-1
9x=1
x=1\9 answer.
Find the volume of each composite figure.
Answer:
630 in^3
Step-by-step explanation:
6 x 6 x 14 = 504
(0.5 x 3 x 6) x 14 = 126
504 + 126 = 630
HELPPPPP
Directions: Find the slope of the lines graphed below.
1.
2.
3.
4.
5.
6.
Directions: Find the slope between the given two points.
7.(-1,-11) and (-6, -7)
8. (-7.-13) and (1, -5)
9. (8.3) and (-5,3)
10. (15, 7) and (3,-2)
11. (-5, -1) and (-5, -10)
12. (-12, 16) and (-4,-2)
Directions: Use slope to determine if lines PQ and RS are parallel, perpendicular, or neither.
13.P(-9,-4), (-7, -1), R(-2,5), S(-6, -1)
m(PO)
m(RS)
Types of Lines
PLEASE HELLPPPP
Answer:
7. -4/5
8. 1
9. 0
10. 3/4
11. undefined/nonlinear
12. -9/4
13. parallel
Simplify
(2½)² x (0,5)²
Answer:
1.5625
Step-by-step explanation:
2½ = 5/2
(5/2)² = 25/4
25/4 = 6.25
0.5² = 0.25
6.25 x 0.25 = 1.5625
What Statistic information we can get from a histogram?
A-Standard Deviation
B-Interquartile Range
C-Mean
Randomly select a painted rock from a bag containing 4 purple rocks, 3 green rocks, 3 orange rocks, and 2 blue rocks.
Answer:
i got a orange
Step-by-step explanation:
The graph of a system of equations is
shown below.
a. (2,0) and (0,3)
b. (-40,-50)
c. the system has no solution
d. the system has infinitely many solutions
Answer:
The system has no solution.
Step-by-step explanation:
In order for the system to have a solution, both graphs must have an intercept to each others. We see in the picture that both graphs are parallel and do not have any interceptions which we don't know the solution to the system.
That means if graphs are parallel and have no interceptions, there are no solutions. The system of equations are for finding the interceptions of both graphs. But of course! Parallel lines do not intercept.
If you have any questions, feel free to ask.