Find the angle between the vectors ????=????+???? and ????=−????+????. (Give an exact answer. Use symbolic notation and fractions where needed.)
Answer:
The angle between them is 60 degrees
Step-by-step explanation:
Given
[tex]a = 2i + j -3k[/tex]
[tex]b = 3i - 2j -k[/tex]
Required
The angle between them
The cosine of the angle between them is:
[tex]\cos(\theta) = \frac{a\cdot b}{|a|\cdot |b|}[/tex]
First, calculate a.b
[tex]a \cdot b =(2i + j -3k) \cdot (3i - 2j -k)[/tex]
Multiply the coefficients of like terms
[tex]a \cdot b =2 * 3 - 1 * 2 - 3 * -1[/tex]
[tex]a \cdot b =7[/tex]
Next, calculate |a| and |b|
[tex]|a| = \sqrt{2^2 + 1^2 + (-3)^2[/tex]
[tex]|a| = \sqrt{14[/tex]
[tex]|b| = \sqrt{3^2 + (-2)^2 + (-1)^2}[/tex]
[tex]|b| = \sqrt{14}[/tex]
Recall that:
[tex]\cos(\theta) = \frac{a\cdot b}{|a|\cdot |b|}[/tex]
This gives:
[tex]\cos(\theta) = \frac{7}{\sqrt{14} * \sqrt{14}}[/tex]
[tex]\cos(\theta) = \frac{7}{14}[/tex]
[tex]\cos(\theta) = 0.5[/tex]
Take arccos of both sides
[tex]\theta =\cos^{-1}(0.5)[/tex]
[tex]\theta =60^o[/tex]
help me pleaseeeeeeeeeeeeeeeeee………….
Answer:
C
Step-by-step explanation:
200 x 5 = 1,000
100 x 10 = 1,000
C - 5 to 10 days
Answer:
C. 5 to 10 days
Step-by-step explanation:
If she drove 100 miles per day, then
1000/100 = 10
it took her 10 days.
If she drove 200 miles per day, then
1000/200 = 5
it took her 5 days.
Since she drove between 100 miles and 200 miles per days,
it took her from 5 to 10 days.
Answer: C. 5 to 10 days
If f(x) is a linear function, what is the value of n?
х
_4
f(x)
---25
-10
-1
n
20
2
оооо
9
Step-by-step explanation:
You can simply plot these points on a graph and see where the line goes. It go
Estimate 19.625-6.77 by first rounding each number to the nearest tenth.
Answer:
13
Step-by-step explanation:
1. Round 19.625 up to 20.
2. Round 6.77 up to 7.
3. Calculate the equation. Ans is 13.
A shopkeeper supplies 42 kg of vegetables to a school canteen in the morning and 58 kg of vegetables in the evening if cost of 1kg vegetable is 16 rupees how much money is due to the canteen per day?
Thane Company is interested in establishing the relationship between electricity costs and machine hours. Data have been collected and a regression analysis prepared using Excel. The monthly data and the regression output follow:
Month Machine Hours Electricity Costs
January 2,300 $ 19,100
February 2,700 $ 22,400
March 1,700 $ 14,200
April 2,900 $ 24,400
May 3,600 $ 28,950
June 3,100 $ 23,400
July 3,900 $ 25,450
August 3,300 $ 23,450
September 1,800 $ 16,900
October 3,500 $ 27,400
November 4,500 $ 32,400
December 4,000 $ 28,450
Summary Output
Regression Statistics
Multiple R 0.957
R Square 0.917
Adjusted R2 0.908
Standard Error 1,586.26
Observations 12.00
Coefficients Standard Error t Stat P-value Lower 95% Upper 95%
Intercept 5,970.52 1,766.77 3.38 0.01 2,033.90 9,907.13
Machine Hours 5.76 0.55 10.49 0.00 4.54 6.98
The percent of the total variance that can be explained by the regression is:
Answer:
0.924
Step-by-step explanation:
R² = 0.854
R = √0.854
R = 0.924
Hence, the correlation Coefficient of electricity tarrif is 0.924 ; this correlation Coefficient value, depicts a strong positive correlation between machine hours and cost of electricity. And can he interpreted to mean that ; Electricity tarrif increases as machine hours increases and also decreases as machine hours decreases.
Describe how the graph of y = |x - 2| - 5 is a transformation of the graph of y = |x|. Use terms such as "shifted", "reflected", "stretched", or "compressed".
Answer:
The original graph was shifted 2 units to the left and 5 units down.
Step-by-step explanation:
y = |x|
From this, we go to: y = |x - 2|.
When we want to shift a function f(x) a units to the left, we find f(x - a). So first, the graph was shifted 2 units to the left.
y = |x - 2|.
From this, we go to: y = |x - 2| - 5.
Shifting a function f(x) down b units is the same as finding f(x) - b, so the second transformation was shifting the graph 5 units down.
Which of the following is true?
Answer:
Step-by-step explanation:
A=45
if the mean of a random variable X is 45 what will be the mean of the sampling distribution of the sample mean?
Answer:
The mean of the sampling distribution is always equal to the mean of the population.
The mean of the sampling distribution of the sample mean is 45.
Given that,
The mean of the random variable X is 45.We need to find out the mean of the sampling distribution.Based on the above information, the calculation is as follows:
= mean of the random variable X
= 45
As the sampling distribution mean should always be equivalent to the population mean.
Therefore we can conclude that the mean of the sampling distribution of the sample mean is 45.
Learn more: brainly.com/question/521501
In the diagram, point D is the center of the medium-sized circle that passes through C and E, and it is also the center of the largest circle that passes through A and G. Each of the diameters of the small circles with centers B and F equals the radius of the medium-sized circle with center D. The shaded area is what fraction of the largest circle?Single choice.
9514 1404 393
Answer:
5/8
Step-by-step explanation:
The area of the smaller circles is proportional to the square of the ratio of their diameters. The two smallest circles have diameters equal to 1/4 the diameter of the largest circle. Hence their areas are (1/4)^2 = 1/16 of that of the largest circle.
Similarly, the medium circle has a diameter half that of the largest circle, so its area is (1/2)^2 = 1/4 of the are of the largest circle.
The smaller circles subtract 2×1/16 +1/4 = 3/8 of the area of the largest circle. Then the shading is 1-3/8 = 5/8 of the area of the largest circle.
How can you use transformations to graph this function?
Answer:
What function?
Step-by-step explanation:
In the coordinate plane, two vertices of square ABCD are A (0,0) and B (0, m). What are the coordinates of points C and D? Do not introduce any new variables.
Answer:
Step-by-step explanation:
As shown in the graph,
A, B, C and D are the vertices of a square, all sides of the square will be equal in measure.
Coordinates of A → (0, 0)
Coordinates of B → (0, m)
Distance between point D and point A = m
Therefore, coordinates of point D → (m, 0)
Now point C will be equally distant from the points B and D.
Coordinates of C → (m, m)
You need
1
1
4
feet of string to make 20 holiday ornaments.
To make 14 holiday ornaments, you will need
feet of string.
Answer:
79.8
Step-by-step explanation:
math
Express each ratio as a fraction in its lowest terms.
18 hours to 2 days
Answer:
3/8.
Step-by-step explanation:
First convert days to hours:
2 days = 2 * 24 = 48 hours.
The greatest common factor of 18 and 48 = 6 so the required fraction is
18/48
= (18/6) / (48/6)
= 3/8.
Because of high tuition costs at state and private universities, enrollments at community colleges have increased dramatically in recent years. The following data show the enrollment (in thousands) for Jefferson Community College for the nine most recent years.
Year Period (t) Enrollment (1,000s)
2001 1 6.5
2002 2 8.1
2003 3 8.4
2004 4 10.2
2005 5 12.5
2006 6 13.3
2007 7 13.7
2008 8 17.2
2009 9 18.1
Required:
a. What type of pattern exists in the data?
b. Use simple linear regression analysis to find the parameters for the line that minimizes MSE for this time series.
c. What is the forecast for year 10?
Answer:
a. A linear pattern exists in the data.
b. The parameters for the line that minimizes MSE for this time series are as folows:
ß1 = Estimated slope = 1.4567
ß0 = Estimated intercept = 4.7165
Also, we have:
MSE = Mean squared error = 0.4896
c. Forecast for year 10 is 19,280.
Step-by-step explanation:
a. What type of pattern exists in the data?
Note: See Sheet1 of the attached excel file for the line graph.
From the line graph, it can be observed that a linear pattern exists in the data.
b. Use simple linear regression analysis to find the parameters for the line that minimizes MSE for this time series.
Note: See Sheet2 of the attached excel file for all the calculations to obtain the following:
Sample size = 9
Total of X = 45
Total of Y = 108
Mean of X = Total of X / Sample size = 45 / 9 = 5
Mean of Y = Total of X / Sample size = 108 / 9 = 12
SSxx = Total of (X - Mean of X)^2 = 60
SSyy = Total of (Y - Mean of Y)^2 = 130.74
SSxy = Total of (X - Mean of X) * (Y - Mean of Y) = 87.40
Therefore, we have:
ß1 = Estimated slope = SSxy/SSxx = 87.4 / 60 = 1.4567
ß0 = Estimated intercept = Mean of Y – (ß1 * Mean of X) = 12 - (5 * 1.4567) = 4.7165
Therefore, the parameters for the line that minimizes MSE for this time series are as folows:
ß1 = Estimated slope = 1.4567
ß0 = Estimated intercept = 4.7165
Regression equation which also used in the attached excel is as follows:
Y = ß0 + ß1X =
Y = 4.7165 + 1.4567X …………………. (1)
SSE = Sum of squared error = Total of (Y - Y*)^2 = 3.4273
Therefore, we have:
MSE = Mean squared error = (SSE/(n-2)) = (3.4273 / (9 - 2)) = 0.4896
c. What is the forecast for year 10?
This implies that X = 10
Substitute X = 10 into equation (1), we have:
Y = 4.7165 + (1.4567 * 10) = 19.28
Since it is 1,000s, we have:
Y = 19.28 * 1,000 = 19,280
Therefore, forecast for year 10 is 19,280.
The endpoints of PC are P(4, 1) and Q(4,8). Find the midpoint of PQ
A. (4, 4.5)
B. (0, -3.5)
C. (4.5, 4)
D. (6, 3.5)
Answer:
A. (4,4.5)
Step-by-step explanation:
Midpoint={x1+x2/2,y1+y2/2}
M={4+4/2,1+8/2}
M={8/2,9/2}
M={4,4.5}
The answer to this 6th grade summer school math question is
Answer 7.84
when a number is added to 1/5 of itself, the result is 24. the equation that models this problem is n+1/5n=24. what is the value of n?
5. In 2015, Texas led the nation in the percentage of people who lacked health insurance (21.6% of the population). It is known that, nationally, 5% of patients account for 50% of the costs of healthcare. These are the “high cost” patients Assume* that: Being a high cost patient and being uninsured are independent characteristics Insured and uninsured people become “patients” at the same rate The uninsured and high cost patients in Texas are evenly distributed across the state, and that high cost patients are evenly distributed across insured and uninsured patient populations a. What is the probability that a patient in a Texas healthcare facility will be a high cost patient who is uninsured?
Answer: 0.108
Step-by-step explanation:
Since the probability of the uninsured is 21.6% of the population, then the probability of insured will be:
= 1 - 21.6%
= 78.4%
The probability of high cost patients is 5%. Therefore, the probability that a patient in a Texas healthcare facility will be a high cost patient who is uninsured will be:
= 5% × 21.6%
= 0.05 × 0.216
= 0.108
What are the roots of the polynomial equation x3 - 6x= 3x2 - 8? Use a graphing calculator and a system of equations
Answer:
Hence, the roots of the polynomial equation are:
-2, 1, 4
Step-by-step explanation:
We are asked to find the roots of the polynomial equation:
We can also equate this equation to y to obtain a system of equation as:
and
Hence, the roots of the polynomial; equation are the x-values of the point of intersections of the graph of the system of equations.
Hence, the point of intersection of the two graphs are:
(-2,4), (1,-5) and (4,40)
Hence, the roots of the polynomial equation are:
-2, 1, 4
NO LINKS OR ANSWERING WHAT YOU DON'T KNOW?
4. Suppose y varies inversely with the x, and y = -1 when = 3. What inverse variation equation relates x and y?
a. y = 3/x
b. b. y = -3x
c. y = 3x
d. y = -3/x
5. Suppose y varies inversely with x and y = 68 when x = 1/17. What is the value of x when y = 16?
a. 64
b. 32
c. 1/4
d. 1/16
6. Suppose y varies inversely with x, and y = 5 when x = 15. What is the value of y when x = 25
a. 3
b. 5
c. 25
d. 15
Answer:
4,a
5.d
6.c
plz mark me as brainliest
Step-by-step explanation:
Answer:
1. A
2. C
3. A
Step-by-step explanation:
all the explanations are In the image above
From the table below, determine whether the data shows an exponential function. Explain why or why not.
x
3
2
1
–1
y
8
2
0.5
0.125
a. No; the domain values are at regular intervals and the range values have a common factor 0.25. b. No; the domain values are not at regular intervals although the range values have a common factor. c. Yes; the domain values are at regular intervals and the range values have a common factor 4. d. Yes; the domain values are at regular intervals and the range values have a common factor 0.25.
9514 1404 393
Answer:
b. No; the domain values are not at regular intervals although the range values have a common factor.
Step-by-step explanation:
The differences between x-values are ...
-1, -1, -1, -2 . . . . not a constant difference
The ratios of y-values are ...
2/8 = 0.5/2 = 0.125/0.5 = 0.25 . . . . a constant difference
The fact that the domain values do not have a common difference renders the common factor of the range values irrelevant. The relation is not exponential.
Given right angle ABC, what the value of tan(A)?
5/13
12/13
12/5
13/12
need answer asap
Hi there!
[tex]\large\boxed{12/5}}[/tex]
tan (angle) = Opposite side / Adjacent side, so:
Tan (A) = opposite side / adjacent side
= 24 / 10
Simplify:
= 12 / 5
SCALCET8 3.9.017.MI. Two cars start moving from the same point. One travels south at 48 mi/h and the other travels west at 20 mi/h. At what rate is the distance between the cars increasing two hours later
Answer:
The rate at which the distance between the cars increasing two hours later=52mi/h
Step-by-step explanation:
Let
Speed of one car, x'=48 mi/h
Speed of other car, y'=20 mi/h
We have to find the rate at which the distance between the cars increasing two hours later.
After 2 hours,
Distance traveled by one car
[tex]x=48\times 2=96 mi[/tex]
Using the formula
[tex]Distance=Time\times speed[/tex]
Distance traveled by other car
[tex]y=20\times 2=40 mi[/tex]
Let z be the distance between two cars after 2 hours later
[tex]z=\sqrt{x^2+y^2}[/tex]
Substitute the values
[tex]z=\sqrt{(96)^2+(40)^2}[/tex]
z=104 mi
Now,
[tex]z^2=x^2+y^2[/tex]
Differentiate w.r.t t
[tex]2z\frac{dz}{dt}=2x\frac{dx}{dt}+2y\frac{dy}{dt}[/tex]
[tex]z\frac{dz}{dt}=x\frac{dx}{dt}+y\frac{dy}{dt}[/tex]
Substitute the values
[tex]104\frac{dz}{dt}=96\times 48+40\times 20[/tex]
[tex]\frac{dz}{dt}=\frac{96\times 48+40\times 20}{104}[/tex]
[tex]\frac{dz}{dt}=52mi/h[/tex]
Hence, the rate at which the distance between the cars increasing two hours later=52mi/h
GM projected that 3% of their cars produced this year will be defective. If GM produced 1,698 cars that were defective, how many cars did GM produce this year
Answer:
56600 cars
Step-by-step explanation:
Below is the calculation of number of cars produced.
The percentage of cars that is defected = 3%
Number of cars that are defective = 1698 cars
The number of cars produced in a year = 1698 / 3%
The number of cars produced in a year = 56600 cars
What is 35 degrees Celsius in Fahrenheit equal
Answer:
95°Fahrenheit
hipe this helps you
The time between surface finish problems in a galvanizing process is exponentially distributed with a mean of 41 hours. A single plant operates three galvanizing lines that are assumed to operate independently. Round your answers to four decimal places (e.g. 98.7654).
(a) What is the probability that none of the lines experiences a surface finish problem in 41 hours of operation?
(b) What is the probability that all three lines experience a surface finish problem between 24 and 41 hours of operation?
Answer:
a) The probability that none of the lines experiences a surface finish problem in 41 hours of operation is 0.0498.
b)The probability that all three lines experience a surface finish problem between 24 and 41 hours of operation is 0.0346.
Step-by-step explanation:
[tex]Mean = \frac{1}{\lambda} = 41\\P(X\leq x)= 1-e^{-\lambda x}[/tex]
[tex]P(X>x)= e^{-\lambda x}[/tex]
a)
[tex]P(x> 41, y>41, Z>41) = (P(X>41))^{3}\\\\P(X>41)=e^{^{-\frac{41}{41}}}=e^{-1}[/tex]
[tex]P(x> 41, y>41, Z>41) = \left (e^{-1} \right )^{3}\\\\P(x> 41, y>41, Z>41) = e^{-3} = 0.0498.[/tex]
b)
[tex]\lambda =\frac{24}{41}\\P(X=1)=e^{-\lambda }\cdot \lambda =\left ( e^{-0.585} \right )\left ( 0.585 \right )\\P(X=1)=0.326[/tex]
For 3 where, P(X=1, Y==1, Z=1)
[tex]= (0.326)^{3} \\\\= 0.0346[/tex]
help me please i am struggle with this
The of the matrix whose columns are vectors which define the sides of a parallelogram one another is the area of the parallelogram?
Answer:
absolute value of the determinant, adjacent to, equal to
Step-by-step explanation:
The absolute value of a determinant of the [tex]\text{matrix whose}[/tex] columns are the vectors and they define the [tex]\text{sides}[/tex] of a [tex]\text{parallelogram}[/tex] which is adjacent to one another and is equal to the [tex]\text{area}[/tex] of the [tex]\text{parallelogram}[/tex].
The determinant is a real number. They are like matrices, but we use absolute value bars to show determinants whereas to represent a matric, we use square brackets.
simplify 6 x + 3y /3
Answer:
6x + y
Step-by-step explanation:
6x + 3y/3
6x + y
Answer:
6x + y
Step-by-step explanation:
6x + 3y / 3
cancel 3y by 3
6x + y
