use undetermined coefficient to determine the solution of:y"-3y'+2y=2x+ex+2xex+4e3x
First check the characteristic solution: the characteristic equation for this DE is
r ² - 3r + 2 = (r - 2) (r - 1) = 0
with roots r = 2 and r = 1, so the characteristic solution is
y (char.) = C₁ exp(2x) + C₂ exp(x)
For the ansatz particular solution, we might first try
y (part.) = (ax + b) + (cx + d) exp(x) + e exp(3x)
where ax + b corresponds to the 2x term on the right side, (cx + d) exp(x) corresponds to (1 + 2x) exp(x), and e exp(3x) corresponds to 4 exp(3x).
However, exp(x) is already accounted for in the characteristic solution, we multiply the second group by x :
y (part.) = (ax + b) + (cx ² + dx) exp(x) + e exp(3x)
Now take the derivatives of y (part.), substitute them into the DE, and solve for the coefficients.
y' (part.) = a + (2cx + d) exp(x) + (cx ² + dx) exp(x) + 3e exp(3x)
… = a + (cx ² + (2c + d)x + d) exp(x) + 3e exp(3x)
y'' (part.) = (2cx + 2c + d) exp(x) + (cx ² + (2c + d)x + d) exp(x) + 9e exp(3x)
… = (cx ² + (4c + d)x + 2c + 2d) exp(x) + 9e exp(3x)
Substituting every relevant expression and simplifying reduces the equation to
(cx ² + (4c + d)x + 2c + 2d) exp(x) + 9e exp(3x)
… - 3 [a + (cx ² + (2c + d)x + d) exp(x) + 3e exp(3x)]
… +2 [(ax + b) + (cx ² + dx) exp(x) + e exp(3x)]
= 2x + (1 + 2x) exp(x) + 4 exp(3x)
… … …
2ax - 3a + 2b + (-2cx + 2c - d) exp(x) + 2e exp(3x)
= 2x + (1 + 2x) exp(x) + 4 exp(3x)
Then, equating coefficients of corresponding terms on both sides, we have the system of equations,
x : 2a = 2
1 : -3a + 2b = 0
exp(x) : 2c - d = 1
x exp(x) : -2c = 2
exp(3x) : 2e = 4
Solving the system gives
a = 1, b = 3/2, c = -1, d = -3, e = 2
Then the general solution to the DE is
y(x) = C₁ exp(2x) + C₂ exp(x) + x + 3/2 - (x ² + 3x) exp(x) + 2 exp(3x)
Solve this pleaseeeeeeeeeee
Answer:
10d
Step-by-step explanation:
5d on 1 side, double it to get 10d cuz from Point O to Point D, y increases from 0 to 5d and since the triangles are congruent, we can add another 5d (or in total 10d).
An office manager has received a report from a consultant that includes a section on equipment replacement. The report indicates that scanners have a service life that is normally distributed with a mean of 41 months and a standard deviation of 4 months. On the basis of this information, determine the proportion of scanners that can be expected to fail within plus or minus 6 months of the mean. (Enter your answer as a percentage without the percent sign; keep 2 decimal places)
Answer:
The answer is "36.14%"
Step-by-step explanation:
The complete question is given in the attached file please find it.
[tex]\mu =41\\\\\sigma= 4\\\\P(42<\bar{x}<48)= p(\bar{x}<48)-p(\bar{x}<42)\\\\Z =\frac{(42-41)}{4} = \frac{1}{4} =0.25\\\\Z =\frac{(48-41)}{4} = \frac{7}{4} = 1.75\\\\[/tex]
Using z-table to find the value.
[tex]\to P(41<\bar{x}<48) = 0.9599- 0.5987 = 0.3614\times 100= 36.14\%[/tex]
This means that between 42 and 48 months, 36.14 % of scanners could be predicted will break down.
Nancy left a bin outside in her garden to collect rain water. She notices the 1/2 gallon fills 2/3 of the bin. Write and solve an equation to find the amount of water that will fill the entire bin. Show your work. Explain your answer in words.
Here we want to solve a question involving fractions, we will find that:
3/4 gallon fils the complete bin.
Ok, so we know that 1/2 gallon of water, fills 2/3 of the bin.
We want to find the total amount of water that would fill the entire bin.
So we could write an equation like:
amount of water = amount of the bin that it fills.
Then, using the above information, we have:
1/2 gal = 2/3 of a bin
Now we want to get at 1 on the right side, this would mean "1 bin"
Then we multiply both sides by (3/2)
(3/2)*(1/2) gal = (3/2)*(2/3) of a bin
3/4 gal = 1 bin
From this, we can conclude that (3/4) gallons of water would fill the complete bin.
If you want to learn more about algebra, you can read:
https://brainly.com/question/4837080
x = 0,75 gallons or x = 3/4 gallons The volume of the bin
The volume of the bin is: In terms of a fraction
1 = 3/3 or any unitary fraction 5/5 7/7 9/9
We will take 3/3 since we have the information that 2/3 of the volume of the bin was filled with 2/3 of a gallon
If 2/3 of the volume of the bin was filled with 1/2 gallon then we make a rule of three according to:
If 0,5 gal. fill 2/3 of the volume of the bin then
x gal fill 3/3 ( the volume of the bin)
solving
0,5 (gal) * 3/3 = (2/3)*x ( The equation)
0,5*3 = 2*x
x = (0,5*3)/2
x = 0,75 gallons or x = 3/4 gallons
Lynbrook West, an apartment complex, has 100 two-bedroom units. The monthly profit (in dollars) realized from renting out x apartments is given by the following function. p(x)=-12x^2+2160x-59000 To maximize the monthly rental profit, how many units should be rented out? units What is the maximum monthly profit realizable?
Answer:
To maximize the monthly rental profit, 90 units should be rented out.
The maximum monthly profit realizable is $38,200.
Step-by-step explanation:
Vertex of a quadratic function:
Suppose we have a quadratic function in the following format:
[tex]f(x) = ax^{2} + bx + c[/tex]
It's vertex is the point [tex](x_{v}, y_{v})[/tex]
In which
[tex]x_{v} = -\frac{b}{2a}[/tex]
[tex]y_{v} = -\frac{\Delta}{4a}[/tex]
Where
[tex]\Delta = b^2-4ac[/tex]
If a<0, the vertex is a maximum point, that is, the maximum value happens at [tex]x_{v}[/tex], and it's value is [tex]y_{v}[/tex].
In this question:
Quadratic equation with [tex]a = -12, b = 2160, c = -59000[/tex]
To maximize the monthly rental profit, how many units should be rented out?
This is the x-value of the vertex, so:
[tex]x_{v} = -\frac{b}{2a} = -\frac{2160}{2(-12)} = \frac{2160}{24} = 90[/tex]
To maximize the monthly rental profit, 90 units should be rented out.
What is the maximum monthly profit realizable?
This is p(90). So
[tex]p(90) = -12(90)^2 + 2160(90) - 59000 = 38200[/tex]
The maximum monthly profit realizable is $38,200.
A sailor on a trans-Pacific solo voyage notices one day that if he puts 625.mL of fresh water into a plastic cup weighing 25.0g, the cup floats in the seawater around his boat with the fresh water inside the cup at exactly the same level as the seawater outside the cup (see sketch at right).
Calculate the amount of salt dissolved in each liter of seawater. Be sure your answer has a unit symbol, if needed, and round it to 2 significant digits.
You'll need to know that the density of fresh water at the temperature of the sea around the sailor is 0.999/gcm3. You'll also want to remember Archimedes' Principle, that objects float when they displace a mass of water equal to their own mass.
Answer:
can you say again please
*20 points*
how do you get the weighted average from this table?
Answer:
it is
[(2+3+4+6)-2*4]:4=1.75
I THINK
Step-by-step explanation:
Jagroop is building a dock at his cottage. The length of the doc is 3 times the width, plus 2. Determine a simplified expression for the perimeter of the doc
Answer:
Step-by-step explanation:
Let length = y width = x
y = 3x + 2
Perimeter = Sum of all sides (or sum of both lengths and both widths)
2y + 2x
2(3x + 2) + 2x
6x + 4 + 2x
8x + 4
You are dealt two cards successively without replacement from a standard deck of 52 playing cards. Find the probability that the first card is a two and the second card is a ten.
Answer:
[tex]\frac{4}{52} \times \frac{4}{51} = \frac{16}{2652} = 0.00603 = 0.603\%[/tex]
Step-by-step explanation:
There are 52 cards in a standard deck, and there are 4 suits for each card. Therefore there are 4 twos and 4 tens.
At first we have 52 cards to choose from, and we need to get 1 of the 4 twos, therefore the probability is just
[tex]\frac{4}{52}[/tex]
After we've chosen a two, we need to choose one of the 4 tens. But remember that we're now choosing out of a deck of just 51 cards, since one card was removed. Therefore the probability is
[tex]\frac{4}{51}[/tex]
Now to get the total probability we need to multiply the two probabilities together
[tex]\frac{4}{52} \times \frac{4}{51} = \frac{16}{2652} = 0.00603 = 0.603\%[/tex]
Please help!!
Find BD
Answer: [tex]8\sqrt{2}[/tex]
==========================================================
Work Shown:
Focus entirely on triangle ABD (or on triangle BCD; both are identical)
The two legs of this triangle are AB = 8 and AD = 8. The hypotenuse is unknown, so we'll say BD = x.
Apply the pythagorean theorem.
[tex]a^2 + b^2 = c^2\\\\c = \sqrt{a^2 + b^2}\\\\x = \sqrt{8^2 + 8^2}\\\\x = \sqrt{2*8^2}\\\\x = \sqrt{8^2*2}\\\\x = \sqrt{8^2}*\sqrt{2}\\\\x = 8\sqrt{2}\\\\[/tex]
So that's why the diagonal BD is exactly [tex]8\sqrt{2}\\\\[/tex] units long
Side note: [tex]8\sqrt{2} \approx 11.3137[/tex]
find x
please help!!
Answer: [tex]9\sqrt{3}[/tex]
==========================================================
Explanation:
For any 30-60-90 triangle, the short leg is always half the hypotenuse.
This makes the short leg to be 18/2 = 9 units long.
We then multiply this by [tex]\sqrt{3}[/tex] to get the length of the long leg.
[tex]\text{long leg} = (\text{short leg})*\sqrt{3}\\\text{long leg} =9\sqrt{3}[/tex]
Or you could use the pythagorean theorem to solve [tex]x^2+9^2 = 18^2[/tex] and you should get [tex]x = \sqrt{243} = 9\sqrt{3}[/tex]
find the area of the shaded regions. ANSWER IN PI FORM AND DO NOT I SAID DO NOT WRITE EXPLANATION
Answer: 18π
okokok gg
Step-by-step explanation:
Here angle is given in degree.We have convert it into radian.
[tex] {1}^{\circ} =( { \frac{\pi}{180} } )^{c} \\ \therefore \: {80}^{\circ} = ( \frac{80\pi}{180} ) ^{c} = {( \frac{4\pi}{9} })^{c} \: = \theta ^{c} [/tex]
radius r = 9 cmArea of green shaded regions = A
[tex] \sf \: A = \frac{1}{2} { {r}^{2} }{ { \theta}^{ c} } \\ = \frac{1}{2} \times {9}^{2} \times \frac{4\pi}{9} \\ = 18\pi \: {cm}^{2} [/tex]
how long does it take for a deposit of $900 to double at 2% compounded continuously?
how many years does it take to double ? ___ years __ days
9514 1404 393
Answer:
34.6574 years34 years, 239.94 daysStep-by-step explanation:
For continuous compounding the "rule of 69" applies. That is the doubling time can be found from ...
t = 69.3147/r . . . . where r is the interest rate in percent.
Here, r=2, so ...
t = 69.3147/2 = 34.6574 . . . years
That's 34 years and 240 days.
A biologist was interested in determining whether sunflower seedlings treated with and an extract from Vinca minor roots resulted in a lower average height of sunflower seedlings that the standard height of 15.7 cm. The biologist treated a random sample of 33 seedlings with the extract and subsequently measured the height of those seedlings. At the 0.01 significance level, is there evidence that the true average height of the seedlings treated with an extract from Vinca minor roots is less than 15.7 cm?
Height
15.5
15.8
15.7
15.1
15.1
15.5
15.2
15.7
15.8
15.4
16.2
15.5
16.2
15.5
15.4
16.3
14.9
15.3
15.1
16.1
15.3
15.4
15.1
15.3
14.6
15.1
15.0
15.3
15.8
15.5
14.8
15.2
14.8
a. State the null and alternative hypotheses.
b. Report the value of the test statistic. Round answer to 2 decimal places. (Either calculate or use software such as minitab)
c. Using the p-value, do you reject the null hypothesis or fail to reject the null hypothesis? Explain your decision.
d. Based on your decision in part (c), write a conclusion within the context of the problem.
Answer:
Kindly check explanation
Step-by-step explanation:
H0 : μ = 15.7
H1 : μ < 15.7
This is a one sample t test :
Test statistic = (xbar - μ) ÷ (s/√(n))
n = sample size = 33
Using calculator :
The sample mean, xbar = 15.41
The sample standard deviation, s = 0.419
Test statistic = (15.41 - 15.70) ÷ (0.419/√(33))
Test statistic = - 3.976
Using the Pvalue calculator :
Degree of freedom, df = n - 1 ; 33 - 1 = 32
Pvalue(-3.976, 32) = 0.000187
Decison region :
Reject H0 if Pvalue < α
Since Pvalue < α ; we reject H0
There is significant evidence to conclude that the true average height of the seedlings treated with an extract from Vinca minor roots is less than 15.7 cm.
Which correlation best describes the data below. no correlation weak positive weak negative strong positive
Scores on a national English test are Normally distributed, with a mean score of 510 and a standard deviation of 75. Sixty-eight percent of English tests were less than which score, rounded to the nearest whole number?
A) 475
B) 529
C) 545
D) 561
Answer:
Should be (C). Can't verify.
545
ED2021
You are offered two stocks. The beta of A is 1.4 while the beta of B is 0.8. The growth rates of earnings and dividends are 10% and 5%, respectively. The dividend yields are 5% and 7%, respectively.
Since A offers higher potential growth, should it be purchased?
Investments- Individual Work 2 Page 3
Since B offers a higher dividend yield, should it be purchased?
If the risk-free rate of return were 7% and the return on the market is expected to be 14%, which of these stocks should be bought?
Answer:
a) Yes , Cause The Expected Returns of stock A is Higher than that of B
b) No, Cause The Expected Returns of stock B is Lower than that of A
Step-by-step explanation:
From the question we are told that:
Beta A \beta A=1.4
Beta B \beta B=0.8
Stock 1 Growth rates of earnings and dividends G_1=10\%
Stock 2 Growth rates of earnings and dividends G_2=5\%
Stock 1 Dividend yields D_1=5\%
Stock 2 Dividend yields D_2=7\%
Generally the equation for Expected Returns is mathematically given by
Expected Returns =Growth rates+Dividend yields
For Stock 1
Expected\ Returns =G_1+D_1
Expected\ Returns =5%+10%
Expected\ Returns =15%
For Stock 2
Expected\ Returns =G_2+D_2
Expected\ Returns =7%+5%
Expected\ Returns =12%
Therefore
a) Yes , Cause The Expected Returns of stock A is Higher than that of B
b) No, Cause The Expected Returns of stock B is Lower than that of A
Using a profit P1 of $5,000, a profit P2 of $4,500, and a profit P3 of $4,000, calculate a 95% confidence interval for the mean profit per customer that SoftBus can expect to obtain. (Round your answers to one decimal place.) Lower Limit Upper Limit
Answer:
Confidence Interval
Lower Limit = $4,233.3
Upper Limit = $4,766.7
With 95% confidence, the mean profit per customer that SoftBus can expect to obtain is between $4,233.30 and $4,766.7 based on the given sample data.
Step-by-step explanation:
The z-score of 95% = 1.96
Profit Mean Square Root
Difference of MD
P1 $5,000 $500 $250,000
P2 4,500 0 0
P3 4,000 -500 $250,000
Total $13,500 $500,000
Mean $4,500 ($13,500/3) $166,667 ($500,000/3)
Standard Deviation = Square root of $166,667 = 408.2
Margin of error = (z-score * standard deviation)/n
= (1.96 * 408.2)/3
= 266.7
= $266.7
Confidence Interval = Sample mean +/- Margin of error
= $4,500 +/- 266.7
Lower Limit = $4,233.3 ($4,500 - $266.7)
Upper Limit = $4,766.7 ($4,500 + $266.7)
Most of the heat loss for outdoor swimming pools is due to surface
evaporation. So, the greater the area of the surface of the pool, the greater
the heat loss. For a given perimeter, which surface shape would be more
efficient at retaining heat: a circle or a rectangle? Justify your answer.
Answer:
rectangle
Step-by-step explanation:
Perimeter of 20 feet
rectangle (square is technically a rectangle):
sides 5 and 5
5*5 = 25ft²
Circle:
20/(2π) = 3.18309...
3.1809...²π = 31.831ft²
Max area of rectangle (i.e. square) has a smaller area than a circle.
Find the Antilog of 547.840
Answer:
It's impossible because the figure is greater than 10
Step-by-step explanation:
[tex]{ \boxed{ \bf{antilog \: of \: x = \frac{x}{ log} = {10}^{x} }}}[/tex]
Therefore:
[tex]{ \sf{anti(547.840) = {10}^{547.840} }} \\ { \tt{ \red{math \: error \: !}}}[/tex]
Hi,there,can you solve this equation.
4x*sqrt(2x-x²)=2x-1
Answer:
Step-by-step explanation:
4x*sqrt(2x-x²)=2x-1
sqrt(2x-x²)=(2x-1)/4x
2x-x² = 4x^2 -4x + 1 /(16x^2)
32x^3 - 16x^4 = 4x^2 -4x + 1
[tex]-16x^4+32x^3-4x^2+4x-1=0\\[/tex]
[tex]x = 1.92887[/tex]
Which number line represents the solutions to 1-2x = 4?
Answer:
The third choice down
Step-by-step explanation:
|-2x| = 4
There are two solutions, one positive and one negative
-2x = 4 and -2x = -4
Divide by -2
-2x/-2 = 4/-2 -2x/-2 = -4/-2
x = -2 and x = 2
Dogsled drivers, known as mushers, use several different breeds of dogs to pull their sleds. One proponent of Siberian Huskies believes that sleds pulled by Siberian Huskies are faster than sleds pulled by other breeds. He times 47 teams of Siberian Huskies on a particular short course, and they have a mean time of 5.2 minutes. The mean time on the same course for 39 teams of other breeds of sled dogs is 5.5 minutes. Assume that the times on this course have a population standard deviation of 1.4 minutes for teams of Siberian Huskies and 1.1 minutes for teams of other breeds of sled dogs. Let Population 1 be sleds pulled by Siberian Huskies and let Population 2 be sleds pulled by other breeds. Step 1 of 2 : Construct a 95% confidence interval for the true difference between the mean times on this course for teams of Siberian Huskies and teams of other breeds of sled dogs
Answer:
The 95% confidence interval for the true difference between the mean times on this course for teams of Siberian Huskies and teams of other breeds of sled dogs is (-0.8276, 0.2276).
Step-by-step explanation:
Before building the confidence interval, we need to understand the central limit theorem and subtraction of normal variables.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
Siberian Huskies:
Sample of 47, mean of 5.2 minutes, standard deviation of 1.4. So
[tex]\mu_1 = 5.2[/tex]
[tex]s_1 = \frac{1.4}{\sqrt{47}} = 0.2042[/tex]
Others:
Sample of 39, mean of 5.5 minutes, standard deviation of 1.1. So
[tex]\mu_2 = 5.5[/tex]
[tex]s_2 = \frac{1.1}{\sqrt{39}} = 0.1761[/tex]
Distribution of the difference:
[tex]\mu = \mu_1 - \mu_2 = 5.2 - 5.5 = -0.3[/tex]
[tex]s = \sqrt{s_1^2+s_2^2} = \sqrt{0.2042^2+0.1761^2} = 0.2692[/tex]
Confidence interval:
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1 - 0.95}{2} = 0.025[/tex]
Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].
That is z with a pvalue of [tex]1 - 0.025 = 0.975[/tex], so Z = 1.96.
Now, find the margin of error M as such
[tex]M = zs[/tex]
In which s is the standard error. So
[tex]M = 1.96(0.2692) = 0.5276[/tex]
The lower end of the interval is the sample mean subtracted by M. So it is -0.3 - 0.5276 = -0.8276.
The upper end of the interval is the sample mean added to M. So it is -0.3 + 0.5276 = 0.2276
The 95% confidence interval for the true difference between the mean times on this course for teams of Siberian Huskies and teams of other breeds of sled dogs is (-0.8276, 0.2276).
I need help
With these
Answer:
"A"
Step-by-step explanation:
a+b >c
a+c>b
b+c>a
~~~~~~~~~~~~
A. T,T,T
B. T,T,F
C. T,F,T
Which of the following theorems verifies that abc wxy
Answer:
C. AA
Step-by-step explanation:
Since m<Y = 27°, then m<W = 27°.
We have two angles of one triangle (A and B) congruent to two angles of the other triangle (W and X).
Answer: C. AA
Write a simple algorithm to add two numbers
Answer:
Write an algorithm to add two numbers entered by user. Step 2: Declare variables num1, num2 and sum. Step 3: Read values num1 and num2. Step 4: Add num1 and num2 and assign the result to sum.
Max needs to paint a wall that is shaped like a square. He knows that the area of the wall is 75 ft2 . He needs to find the height of the wall. Find the height of the wall to the nearest tenth of a foot.
Answer:
8.7 feet
Step-by-step explanation:
Use the square area formula, a = s², where s is the side length of the square.
Plug in the area and solve for s:
a = s²
75 = s²
√75 = s
8.7 = s
So, to the nearest tenth of a foot, the height is 8.7 feet
A store is having a sale on chocolate chips and walnuts. For 8 pounds of chocolate chips and 3 pounds of walnuts, the total cost is $34. For 2 pounds of chocolate chips and 5 pounds of walnuts, the total cost is $17. Find the cost for each pound of chocolate chips and each pound of walnuts.
Answer:
chocolate chips are $2.00 per pound.
nd walnuts must be $3.50 per pound.
Step-by-step explanation:
Let x be the price of walnuts and y the price of chocolate chips.
2x + 5y = 17 (i)
8x + 3y = 34 (ii)
Multiply (i) by 4 to get
8x + 20y = 68
Subtract (ii) to get
17y = 34
Dividing by 17, we see that chocolate chips are $2.00 per pound.
Substituting y=2 in (i) or (ii), walnuts must be $3.50 per pound.
There is a sales tax of S6 on an item that costs 888 before tax. The sales tax on a second item is $21. How much does the second item cost before tax?
Step-by-step explanation:
before Tax
Coast = 888
in 2ND Item = $21
• 888/21
= $42.28
A rocket is launched at t = 0 seconds. Its height, in meters above sea-level, is given by the equation
h = -4.9t2 + 112t + 395.
At what time does the rocket hit the ground? The rocket hits the ground after how many seconds
Answer:
Step-by-step explanation:
In order to find out how long it takes for the rocket to hit the ground, we only need set that position equation equal to 0 (that's how high something is off the ground when it is sitting ON the ground) and factor to solve for t:
[tex]0=-4.9t^2+112t+395[/tex]
Factor that however you are factoring in class to get
t = -3.1 seconds and t = 25.9 seconds.
Since time can NEVER be negative, it takes the rocket approximately 26 seconds to hit the ground.
