Answer:
Step-by-step explanation:
Let many universities and colleges have conducted supplemental instruction(SI) programs. In that a student facilitator he meets the students group regularly who are enrolled in the course to promote discussion of course material and enhance subject mastery.
Here the students in a large statistics group are classified into two groups:
1). Control group: This group will not participate in SI and
2). Treatment group: This group will participate in SI.
a)Suppose they are samples from an existing population, Then it would be the population of students who are taking the course in question and who had supplemental instruction. And this would be same as the sample. Here we can guess that this is a conceptual population - The students who might take the class and get SI.
b)Some students might be more motivated, and they might spend the extra time in the SI sessions and do better. Here they have done better anyway because of their motivation. There is other possibility that some students have weak background and know it and take the exam, But still do not do as well as the others. Here we cannot separate out the effect of the SI from a lot of possibilities if you allow students to choose.
The random assignment guarantees ‘Unbiased’ results - good students and bad are just as likely to get the SI or control.
c)There wouldn't be any basis for comparison otherwise.
Use the power series method to solve the given initial-value problem. (Format your final answer as an elementary function.)
(x − 1)y'' − xy' + y = 0, y(0) = −7, y'(0) = 3
You're looking for a solution of the form
[tex]\displaystyle y = \sum_{n=0}^\infty a_n x^n[/tex]
Differentiating twice yields
[tex]\displaystyle y' = \sum_{n=0}^\infty n a_n x^{n-1} = \sum_{n=0}^\infty (n+1) a_{n+1} x^n[/tex]
[tex]\displaystyle y'' = \sum_{n=0}^\infty n(n-1) a_n x^{n-2} = \sum_{n=0}^\infty (n+1)(n+2) a_{n+2} x^n[/tex]
Substitute these series into the DE:
[tex]\displaystyle (x-1) \sum_{n=0}^\infty (n+1)(n+2) a_{n+2} x^n - x \sum_{n=0}^\infty (n+1) a_{n+1} x^n + \sum_{n=0}^\infty a_n x^n = 0[/tex]
[tex]\displaystyle \sum_{n=0}^\infty (n+1)(n+2) a_{n+2} x^{n+1} - \sum_{n=0}^\infty (n+1)(n+2) a_{n+2} x^n \\\\ \ldots \ldots \ldots - \sum_{n=0}^\infty (n+1) a_{n+1} x^{n+1} + \sum_{n=0}^\infty a_n x^n = 0[/tex]
[tex]\displaystyle \sum_{n=1}^\infty n(n+1) a_{n+1} x^n - \sum_{n=0}^\infty (n+1)(n+2) a_{n+2} x^n \\\\ \ldots \ldots \ldots - \sum_{n=1}^\infty n a_n x^n + \sum_{n=0}^\infty a_n x^n = 0[/tex]
Two of these series start with a linear term, while the other two start with a constant. Remove the constant terms of the latter two series, then condense the remaining series into one:
[tex]\displaystyle a_0-2a_2 + \sum_{n=1}^\infty \bigg(n(n+1)a_{n+1}-(n+1)(n+2)a_{n+2}-na_n+a_n\bigg) x^n = 0[/tex]
which indicates that the coefficients in the series solution are governed by the recurrence,
[tex]\begin{cases}y(0)=a_0 = -7\\y'(0)=a_1 = 3\\(n+1)(n+2)a_{n+2}-n(n+1)a_{n+1}+(n-1)a_n=0&\text{for }n\ge0\end{cases}[/tex]
Use the recurrence to get the first few coefficients:
[tex]\{a_n\}_{n\ge0} = \left\{-7,3,-\dfrac72,-\dfrac76,-\dfrac7{24},-\dfrac7{120},\ldots\right\}[/tex]
You might recognize that each coefficient in the n-th position of the list (starting at n = 0) involving a factor of -7 has a denominator resembling a factorial. Indeed,
-7 = -7/0!
-7/2 = -7/2!
-7/6 = -7/3!
and so on, with only the coefficient in the n = 1 position being the odd one out. So we have
[tex]\displaystyle y = \sum_{n=0}^\infty a_n x^n \\\\ y = -\frac7{0!} + 3x - \frac7{2!}x^2 - \frac7{3!}x^3 - \frac7{4!}x^4 + \cdots[/tex]
which looks a lot like the power series expansion for -7eˣ.
Fortunately, we can rewrite the linear term as
3x = 10x - 7x = 10x - 7/1! x
and in doing so, we can condense this solution to
[tex]\displaystyle y = 10x -\frac7{0!} - \frac7{1!}x - \frac7{2!}x^2 - \frac7{3!}x^3 - \frac7{4!}x^4 + \cdots \\\\ \boxed{y = 10x - 7e^x}[/tex]
Just to confirm this solution is valid: we have
y = 10x - 7eˣ ==> y (0) = 0 - 7 = -7
y' = 10 - 7eˣ ==> y' (0) = 10 - 7 = 3
y'' = -7eˣ
and substituting into the DE gives
-7eˣ (x - 1) - x (10 - 7eˣ ) + (10x - 7eˣ ) = 0
as required.
[tex]f(x)=e^{3x} .sinx[/tex] . tính [tex]d^{2} f(0)[/tex]
Answer:
6
Step-by-step explanation:
đạo hàm cấp 2 của f(x) rồi thế 0 vào
Based on what we have learned, how can we ensure that we choose a sample of students that is representative of all 8:00 AM classes that take place on a given morning
Sampling technique is a way of selecting a sample from a given population. The best way to get a sample of students that represents all 8:00 AM classes is by using a stratified sampling technique.
From the complete question, we can summarize the given data as follows:
[tex]Buildings = 3[/tex] ----3 buildings in the college
[tex]Lecture\ Halls =2[/tex] ---- 2 lecture halls in each building
[tex]Capacity = 100[/tex] --- 100 students in each lecture hall
Because the students' lecture halls are not in the same building, the best way to get a sample is as follows:
Divide the students into groups (In this case, the students will be grouped by the buildings of their lecture halls)The number of students in each building is:
[tex]Students = Capacity \times Lecture\ Halls[/tex]
[tex]Students = 100 \times 2[/tex]
[tex]Students = 200[/tex]
There are 200 students in each building
Then select at random an equal proportion of student from each building (say 30 students in each building)The above method is referred to as a stratified sampling technique because the population of the students are divided into groups, before being randomly selected.
Read more about sampling techniques at:
https://brainly.com/question/9612230
[tex] \frac{2}{3} \times \frac{2}{3} \times \frac{2}{3} = what[/tex]
Answer I'll make and mark as brainlist.
Answer Fast.
Post on - 2 Aug 2021
3. Find F(3).
F(x)=-x^3+4x^2-2x
Answer:
To Find F(3) you just have to replace x=3 so:
F(3)= -3^3 + 4×3^2 -2×3 = -27 +4×9 - 6 = -33 + 36 = 3
which one of these points lies on the line described by the equation below y - 5 = 6 ( x - 7 )
Answer:
the answer would be (7,5)
A basketball player made 5 baskets during a game. Each basket was worth either 2 or 3 points. How many different numbers could represent the total points scored by the player?
What is the slope? Please Help
Answer:
-1
Step-by-step explanation:
Pick two points on the line
(0,2) and (2,0)
Using the slope formula
m = ( y2-y1)/(x2-x1)
= ( 0-2)/(2-0)
= -2/2
= -1
Answer:
-1
Step-by-step explanation:
Use two points on the line to find the slope, using rise over run.
We can use the points (0, 2) and (2, 0).
From the first point to the other, the y value decreases by 2 and the x value increases by 2.
Use rise (change in y value) over run (change in x value):
-2 / 2
= -1
So, the slope is -1.
help whats the volume of this
Answer:
93.6
Step-by-step explanation:
The easiest way for me to complete this was to break it up into parts. I Separated the small triangle and the big triangle. I turned them both into squares and multiplied the dimensions. I then divided those by two and added them together.
Which expression is equivalent to the given expression?
Answer:
a³b
Step-by-step explanation:
(ab²)³/b⁵
= a³b⁶/b⁵
= a³b
John and mike got paid $40.00 for washing
car. John work one hour, mike worked 1.5 hrs.
How much do they get paid for time worked?
Multiply (2x-5)(x+3)
Answer:
2x^2+x-15
Step-by-step explanation:
foil
Answer:
2x^2 + x - 15
Step-by-step explanation:
using FOIL
(2x - 5)(x + 3)
[(2x ⋅ x) + (2x ⋅ 3) + (-5 ⋅ x) + (-5 ⋅ 3)]
[2x^2 + 6x - 5x - 15]
2x^2 + x - 15
Solve the equation by factoring: 5x^2 - x = 0
Answer:
Step-by-step explanation:
x = 0, 1/5
in the given circle the radius is 9 cm what is its diameter?
Answer:
18
Step-by-step explanation:
The diameter is equal to twice the length of the radius
So if the radius is 9 then the diameter is 9 * 2 = 18
The LARGEST angle has a measure of ______degrees
Answer:
90 i think
Step-by-step explanation:
slope of (30, 600) (75, 1050)
Answer:
y2-y1/x2-x1
y2: 1050
y1:600
x2:75
x1:30
1050-600=450
75-30=45
450/45=10
slope is 10
Answer:
let:
A(30, 600)=(x1,y1)
B((75, 1050)=(x2,y2)
now,
[tex]slope(m) = \frac{y2 - y1}{x2 - x1} [/tex]
[tex] = \frac{1050 - 600}{75 - 30} [/tex]
[tex] = \frac{450}{ 45} [/tex]
[tex] = \frac{10}{1} [/tex]
If we decrease a dimension on a figure, how is the figure’s area affected?
The area decreases.
The area increases.
The area becomes 0.
The area remains the same.
Answer:
A) area decreases
Step-by-step explanation:
Example: we have a 2 by 3 rectangle with area of 2*3 = 6. If we cut the first dimension in half, then we have a 1 by 3 rectangle that has area 1*3 = 3. The area has decreased. To keep the area the same, we would have to increase the other dimension some specific amount.
HOPE THIS HELPS
HAVE A GOOD DAY :)
ITS RASPUTIN002
(-72)(-15)= explain
In which direction does the parabola x=2y2+1 open?
A up
B down
C Right
D left
Answer and Step-by-step explanation:
First, we need to set this equation equal to y, which means we need to get y by itself, and all other terms equal to y.
x = [tex]2y^2 + 1[/tex]
Subtract 1, then divide by 2 on both sides.
[tex]x - 1 = 2y^2\\\\\frac{x-1}{2} = y^2[/tex]
Now, take the square root of both sides.
[tex]y=\sqrt{\frac{x-1}{2}}[/tex]
We see that the value with the x (1) is positive, and that we have a square root function, which means the parabola would open to the right.
(If the x value was negative, the square root function's parabola would open to the left)
So, C (Right) is the correct answer.
#teamtrees #PAW (Plant And Water)
I hope this helps!
Oh Brian~
I need help again
Answer:
18c^3d^9
Step-by-step explanation:
2c^3 d^2 * 9d^7
We know that we add the exponents when the base is the same
2*9 c^3 d^(2+7)
18c^3d^9
Find the missing segment in the image below
Answer:
The missing segment length is 20.
Step-by-step explanation:
2 is multiplied by 4 to get to 8, so 5 must be multiplied by 4 to get to 20.
Using the formula D = s:t where D equals distance traveled, r equals the average rate of
speed, and t equals the time traveled, choose the expression or equation that correctly
represents this information.
Mary drove 150 miles in three hours. What was her average rate of speed?
=
150 = 3
r = 3 = 150
O p + 150 · 3
Answer: r = 50 miles/h
Step-by-step explanation:
Let r be the rate of average speed.
Then
r = D/t
r = 150/3
r = 50 miles/h
please click thanks and mark brainliest if you like :)
2012
Descriptive Answer Questions
Attempt FIVE questions.
11.
Show the Fisher's ideal index number satisfies both time reversal test and factor
reversal test from the following information
Commodities
2010
Price Expenditure
Price
Expenditure
5
4
32
72
х
6
50
5
28
Y
4
3
18
40
Z
8
40
50
3 XN
10
If two numbers differ by 9 the same of their squares is 653. What are the numbers?
Answer:
Two numbers differ by 9 and the sum of their square is 653. What are the numbers?
Well,that's a mathematical question from algebra and it's quite difficult to answer such questions by writing through the circumstances offered by apps like quora.
However,I have tried to answer your question in an understandable way.Hope you may not find it difficult to analyze.
Let the numbers be x and (9+x)
Therefore,according to given,
x^2 + (9+x)^2 =653
=>x^2 + (9)^2 + x^2 + 2×(9)×(x)=653 (Applying the formula of (a+b)^2)
=>x^2 + 81 + x^2 + 18x =653
=>2x^2 + 18x + (81-653)=0
=>2x^2 + 18x - 572=0
=>2x^2 + (44x - 26x) - 572=0
=>2x^2 + 44x - 26x - 572=0
=>2x(x + 22) - 26(x + 22)=0
=>(x + 22)(2x - 26)=0
But since the number can't be negative
Therefore, x=13
Hence,the required numbers are 13 and 22.
Step-by-step explanation:
in first hope you like it
Find the average rate of change of g(x) = 2x^3 - 5 from x= -4 to x= 2
Step-by-step explanation:
the average change rate is the change of the functional values from the beginning to the end of the interval, and then that divided by the length of the interval.
like with every average or mean value calculation.
g(-4) = 2×(-4)³ - 5 = -128 - 5 = -133
g(2) = 2×2³ - 5 = 16 - 5 = 11
so, on an interval of x values of 2- -4 = 6 units the function changes its values by 11 - -133 = 144 units.
the average charge rate for this x interval is therefore
144 / 6 = 24 = 24/1
for 1 unit change of x, g(x) changes in the average by 24 units.
which of the following equations has both 1 and -3 as a solution?
A). x^2-2x-3=0
B). x^2+2x-3=0
C). x^2-4x+3=0
D). x^2+4x+3=0
The population model given dP/dt â P or dP dt = kP (1)
fails to take death into consideration; the growth rate equals the birth rate. In another model of a changing population of a community it is assumed that the rate at which the population changes is a net rate that is, the difference between the rate of births and the rate of deaths in the community. Determine a model for the population P(t) if both the birth rate and the death rate are proportional to the population present at time t > 0.
Answer:
.
Step-by-step explanation:
What is the domain of the function in the graph?
Answer:
7≤r≤12
Step-by-step explanation:
The domain is the values that the input takes
The input goes from 7 to 12
7≤r≤12
Answer: Choice B) [tex]7 \le r \le 12[/tex]
=============================================================
Explanation:
The domain is the set of allowed x inputs of a function.
How far to the left can we go on this red line? That would be x = 7.
How far to the right? That would be x = 12.
We can have x equal anything between 7 and 12, including both endpoints. We include the endpoints because they are filled in circles (as opposed to open holes).
So the domain is [tex]7 \le x \le 12[/tex]. If we replace x with r, then we update that inequality into [tex]7 \le r \le 12[/tex]. This replacement happens because r is along the horizontal x axis.
In the figure PQ || RS, find the value of x.
The value of x in the figure is 125°
And the right option is (D) 125°
To solve the problem, we use the formular for the sum of the interior angle of a polygon.
(n-2)180°
When a vertical line is drawn to touch point Q and S, it becomes a pentagon.Pentagon: A pentagon is a polygon with 5 sidesThe sum of the angle in a pentagon is[tex](5-2)180 = 540[/tex]
From the figure,∠P+∠T+∠R+∠Q+∠S = 540°
[tex]35+200+x+90+90 = 540[/tex]
[tex]415+x = 540[/tex]
[tex]x = 540-415[/tex]
[tex]x = 125[/tex]
Hence the value of x in the figure is 125°
And the right option is (D) 125°
Learn more about polygons here: https://brainly.com/question/17042929
DVD Video Rentals (Refer to Example 3.) The func-
tion V computes the percent share of disc DVD rentals
accounted for by various companies. This function is
defined by V(R) = 37, V(N) = 30, and V(S) = 17,
where R is Redbox, N is Netflix, and S is rental stores.
(Source: Business Insider.)
(a) Write V as a set of ordered pairs.
(b) Give the domain and range of V.
T
Answer:
[tex](a)\ V = \{(N,30),(R,37),(S,17)\}[/tex]
[tex](b)[/tex]
[tex]Domain = \{N,R,S\}[/tex]
[tex]Range = \{37,30,17\}[/tex]
Step-by-step explanation:
Given
[tex]V(R) = 37,\ V(N) = 30,\ V(S) = 17[/tex]
Solving (a): Set of ordered pair
A function y = f(x) is represented as (x,y)
So, the ordered pair of V is:
[tex]V = \{(R,37),(N,30),(S,17)\}[/tex]
Order the alphabets in increasing order
[tex]V = \{(N,30),(R,37),(S,17)\}[/tex]
Solving (b): The domain and the range
In a function [tex]\{(x_1,y_1),...,(x_n,y_n)\}[/tex]
The domain and the range are represented as:
[tex]Domain = \{x_1,x_2....x_n\}[/tex]
[tex]Range = \{y_1,y_2....y_n\}[/tex]
So, we have:
[tex]Domain = \{N,R,S\}[/tex]
[tex]Range = \{37,30,17\}[/tex]
