Answer:
0
Step-by-step explanation:
Differential Equation
1. The given equation is probably supposed to read
y'' - 2y' - 3y = 64x exp(-x)
First consider the homogeneous equation,
y'' - 2y' - 3y = 0
which has characteristic equation
r² - 2r - 3 = (r - 3) (r + 1) = 0
with roots r = 3 and r = -1. Then the characteristic solution is
[tex]y = C_1 e^{3x} + C_2 e^{-x}[/tex]
and we let y₁ = exp(3x) and y₂ = exp(-x), our fundamental solutions.
Now we use variation of parameters, which gives a particular solution of the form
[tex]y_p = u_1y_1 + u_2y_2[/tex]
where
[tex]\displaystyle u_1 = -\int \frac{64xe^{-x}y_2}{W(y_1,y_2)} \, dx[/tex]
[tex]\displaystyle u_2 = \int \frac{64xe^{-x}y_1}{W(y_1,y_2)} \, dx[/tex]
and W(y₁, y₂) is the Wronskian determinant of the two fundamental solutions. This is
[tex]W(y_1,y_2) = \begin{vmatrix}e^{3x} & e^{-x} \\ (e^{3x})' & (e^{-x})'\end{vmatrix} = \begin{vmatrix}e^{3x} & e^{-x} \\ 3e^{3x} & -e^{-x}\end{vmatrix} = -e^{2x} - 3e^{2x} = -4e^{2x}[/tex]
Then we find
[tex]\displaystyle u_1 = -\int \frac{64xe^{-x} \cdot e^{-x}}{-4e^{2x}} \, dx = 16 \int xe^{-4x} \, dx = -(4x + 1) e^{-4x}[/tex]
[tex]\displaystyle u_2 = \int \frac{64xe^{-x} \cdot e^{3x}}{-4e^{2x}} \, dx = -16 \int x \, dx = -8x^2[/tex]
so it follows that the particular solution is
[tex]y_p = -(4x+1)e^{-4x} \cdot e^{3x} - 8x^2\cdot e^{-x} = -(8x^2+4x+1)e^{-x}[/tex]
and so the general solution is
[tex]\boxed{y(x) = C_1 e^{3x} + C_2e^{-x} - (8x^2+4x+1) e^{-x}}[/tex]
2. I'll again assume there's typo in the equation, and that it should read
y''' - 6y'' + 11y' - 6y = 2x exp(-x)
Again, we consider the homogeneous equation,
y''' - 6y'' + 11y' - 6y = 0
and observe that the characteristic polynomial,
r³ - 6r² + 11r - 6
has coefficients that sum to 1 - 6 + 11 - 6 = 0, which immediately tells us that r = 1 is a root. Polynomial division and subsequent factoring yields
r³ - 6r² + 11r - 6 = (r - 1) (r² - 5r + 6) = (r - 1) (r - 2) (r - 3)
and from this we see the characteristic solution is
[tex]y_c = C_1 e^x + C_2 e^{2x} + C_3 e^{3x}[/tex]
For the particular solution, I'll use undetermined coefficients. We look for a solution of the form
[tex]y_p = (ax+b)e^{-x}[/tex]
whose first three derivatives are
[tex]{y_p}' = ae^{-x} - (ax+b)e^{-x} = (-ax+a-b)e^{-x}[/tex]
[tex]{y_p}'' = -ae^{-x} - (-ax+a-b)e^{-x} = (ax-2a+b)e^{-x}[/tex]
[tex]{y_p}''' = ae^{-x} - (ax-2a+b)e^{-x} = (-ax+3a-b)e^{-x}[/tex]
Substituting these into the equation gives
[tex](-ax+3a-b)e^{-x} - 6(ax-2a+b)e^{-x} + 11(-ax+a-b)e^{-x} - 6(ax+b)e^{-x} = 2xe^{-x}[/tex]
[tex](-ax+3a-b) - 6(ax-2a+b) + 11(-ax+a-b) - 6(ax+b) = 2x[/tex]
[tex]-24ax+26a-24b = 2x[/tex]
It follows that -24a = 2 and 26a - 24b = 0, so that a = -1/12 = -12/144 and b = -13/144, so the particular solution is
[tex]y_p = -\dfrac{12x+13}{144}e^{-x}[/tex]
and the general solution is
[tex]\boxed{y = C_1 e^x + C_2 e^{2x} + C_3 e^{3x} - \dfrac{12x+13}{144} e^{-x}}[/tex]
Ali’s cow gives 2 1/4 gallons of milk each day. How much is this in quarts? Write your answer as whole number or a mixed number In simplest form. Include the correct unit in your answer.
Answer:
9 quarts
Step-by-step explanation:
What equation represents this graph?
An 18 foot long ramp is placed at a loading dock that is 5 feet above ground. How far is the bottom of the ramp from the dock?
Answer:
sqrt299
Step-by-step explanation:
Because the loading dock and the ground are perpendicular we know that they are at a 90° angle. Therefore we can use the equation :
a=5
b= ?
c=18
(Then we can move all of the numbers together but what you do to one side you must do to the other)
Therefore,
(Now to make b a single variable we must square root both sides)
Therefore,
Now with all of these as numbers, we can plug this into a calculator *For all of those who have teachers who need EVERY Step see below I continue
Where and
(approximately)
What is the distance between the points (6, 11) and (3, 1)? If necessary, round
your answer to two decimal places.
A. 109 units
B. 9.43 units
C. 10.44 units
D. 89 units
Answer:
C.) 10.44030650
Step-by-step explanation:
Answer:
C. 10.44 unitsStep-by-step explanation:
Use distance formula:
[tex]d=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]Substitute the values and calculate:
[tex]d=\sqrt{(3-6)^2+(1-11)^2} =\sqrt{(-3)^2+(-10)^2} =\sqrt{9+100} =\sqrt{109} =10.4403[/tex]Correct choice is C
Wawra has a collection of 9 books. He compared his collection with shemal and found that shemal has 3 books fewer than he does. Write an equation showing this, using b as the number of books shemal has.
Answer:
9-3=b
Step-by-step explanation:
9-3=b
Answer:
B=6
Step-by-step explanation:
Let "b" be the number of books Shemel has.
Let "a" be the number of books Wawra has.
Eqution:
A-3=B ("3" is given in question)
9-3=B (Substituting with variables given)
B=9-3
B=6
Hence, Shemel has "6" books.
Hope it helps !
Looking at the equation y=(x+3)^2-4, determine which direction in which the parabola is open.
up
down
left
right
link/random words or letters as answer = report
Answer:
parabola opens up
Step-by-step explanation:
The equation of a parabola in vertex form is
y = a(x - h)² + k
where (h, k) are the coordinates of the vertex and a is a multiplier
• If a > 0 then parabola opens up
• If a < 0 then parabola opens down
y = (x + 3)² - 4 ← is in vertex form
with a = 1
Since a > 0 then parabola opens up
amy is building a house. the basement floor is at -15 feet, The roof of the house is above the ground 25 feet. Write an inequality to compare the heights.
Answer:
25/15
Step-by-step explanation:
i really need help last question PLEASE
Answer:
c
Step-by-step explanation:
its in the middle of all the data
f(x) = 9x ^ 2 - 3 then what is f(3) ? Work must be shown for this problem or no credit will be earned.
Answer:
f ( 3 ) = 81
Step-by-step explanation:
→ Substitute in x = 3
9 × 3² - 3
→ Simplify
9 × 9 - 3
→ Simplify again
78
Given that m||n, find the value of x.
Answer:
x = 24°
Step-by-step explanation:
Using 180-degree formula, we can find x.
=> 84 + 4x = 180°
=> 4x = 180 - 84
=> 4x = 96
=> 24°
Therefore, x = 24°
Hoped this helped.
Answer:
[tex] {\boxed {\sf{x = 24 \degree}}}[/tex]
Step-by-step explanation:
In the given figure we have two consecutive interior angles.
We know that each pair of consecutive interior angles is supplementary.
So,
4x+84 = 1804x = 180 - 844x = 96x = 96/4x = 24Therefore, x = 24°
A bus company uses a grid to locate bus stops. The bus station is at (3, 4). The point (7, 6) represents the first bus stop. The location of each stop after that is determined using the same relationships as those between the coordinates of the bus station and the first bus stop. A coordinate plane is titled Which point represents the fourth bus stop? A. (11, 8) B. (13, 12) C. (15, 10) D. (19, 12)
Answer:
D. (19,12)
Step-by-step explanation:
For each bus stop, the X coordinate increases 4, and the Y coordinate increases 2.
Name x y Point
bus station: 3 4 (3,4)
1st bus stop: 7 6 (7,6)
2nd bus stop: 11 8 (11,8)
3rd bus stop: 15 10 (15,10)
4th bus top: 19 12 (19,12)
Answer:
Step-by-step explanation:
19,12
Gayla’s mom bought 9.5 gallons of gas for $21.85 . What is the cost of a gallon of gas?
Answer:
$2.30
Step-by-step explanation:
a chef is going to use a mixture of two brands of Italian dressing. The first brand contains 5% vinegar and the second Brian contains 15% vinegar. The chef wants to make 390 mL of a dressing that is 8% vinegar. How much of each brand should she use?
Answer:
273 mL of 5%117 mL of 15%Step-by-step explanation:
Let q represent the quantity of 15% dressing used. Then the amount of 5% dressing is (390 -q). The amount of vinegar in the mix is ...
0.15q + 0.05(390 -q) = 0.08(390)
0.10q = 31.2 -19.5 = 11.7 . . . . . . subtract 0.05(390) and simplify
q = 117 . . . . . . . . . . . . . . . . . . multiply by 10
390-q = 273
The chef should use 273 mL of the first brand (5% vinegar) and 117 mL of the second brand (15% vinegar).
__
Additional comment
You may have noticed that the value of q is (0.08 -0.05)/(0.10 -0.05)×390. The fraction of the mix that is the highest contributor is the ratio of the difference between the mix value and least contributor, divided by the difference between the contributors: (8-5)/(15-5) = 3/10, the fraction that is 15% vinegar. This is the generic solution to mixture problems.
Learning Task 2: Solve each proportion
1) 5/12 = 35/ n
2) n/ 52 = 180/ 120
3) 18/n = 21/28
4) n/4 = 24/6
5) 10/16 = n/56
1. [tex] \frac{5}{12} = \frac{35}{n} \\ 5n = 35 \times 12 \\ 5n = 420 \\ n = \frac{420}{5} \\ n = 84[/tex]
2. [tex] \frac{n}{52} = \frac{180}{120} \\ 120n = 180 \times 52 \\ 120n = 9360 \\ n = \frac{9360}{120} \\ n = 78[/tex]
Fighting for my life rn
Answer:
I think the other side on top is 129 degrees
Step-by-step explanation:
Im not 100 percent sure sorry if im wrong!!!
How long is a distance of 8 km if measured on a map with a scale of 1:50,000?
Answer: 400,00 km
Step-by-step explanation: 1:50,000 = 8:x
8 * 50,000 = 400,000
So, 8km on the map is 400,000 km in real life.
Would appreciate brainly <3
Write as a fraction
3÷151
Answer:
3/151
Step-by-step explanation:
That's the answer
how do I erase this?
Answer:
By deleting the question, or getting it deleted.
Step-by-step explanation:
How many pints are equivalent to 2 1/4 gallons.
Answer:
21.6171
Step-by-step explanation:
Have a great day!
Solve the system of equations by the addition method.
2x - 5y = 4
7x - 2y = 4
Type in ordered pair.
Answer:
0.400
Step-by-step explanation:
Slope = 0.800/2.000 = 0.400
x-intercept = 4/2 = 2
y-intercept = 4/-5 = -0.80000
1. (5 points) Suppose over the past 6 years, you have earn annual raises.
6
Three times your raise was 4%, twice you received only a 2% raise and one
you received a 10% raise. If your current salary is $85,000, what was your
salary before all of those raises?
9514 1404 393
Answer:
$66,027.66
Step-by-step explanation:
The multiplier for the salary with each raise is (1 + raise). That means the original salary is multiplied by ...
(1.04^3)×(1.02^2)×(1.10) = 1.28733935616 = k
Your original salary (O) satisfies ...
O×k = $85,000
O = $85,000/k ≈ $66,027.66 . . . original salary
The cost of 1 m ribbon is ₹ 75. Find the cost of 7/5 metres of ribbon
Given that
The cost of 1 m ribbon = Rs.75
The cost of 7/5 m ribbon
→ (7/5)×75
→ (7×75)/5
→7×15
→₹ 105
The cost of 7/5 m ribbon is ₹105.
A racing car consumes a mean of 85 gallons of gas per race with a standard deviation of 7 gallons. If 39 racing cars are randomly selected, what is the probability that the sample mean would differ from the population mean by greater than 3 gallons
Answer:
33.20% probability that the sample mean would differ from the population mean by greater than 1 gallon
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
True or false? The point (−5, 0) lies on the y-axis.
\well the answrnist that brcause if u think it guys up
Prepare an accounting equation for the following business transaction
1. Purchased supplies on account, 4,000
2. Purchased furniture and fixtures for cash, 3,000
3. Paid account in no. 1.
4. Paid advance advertisement for promoting the business 1,000
5. Paid the note 2,000
Answer:
you draw a T. form and then you can start to in debit and credit
3) The recipe calls for 6 cups of flour for every 2 1/3 cups of sugar. How many cups of flour
are needed per cup of sugar?
Answer:
Im pretty sure its 3 cups
Step-by-step explanation:
I will give brainlist to the most helpful answer
Answer:
1. 4
2. 6
3. 10
4. 30
5. 48
6. 55
7. 68
8. 148
9. 102
10. 38
Ophira’s insurance company has notified her that her premiums will increase due to a poor insurance score and a recent claim she filed. The recent claim has increased her premiums by 41%, and her poor insurance score will cost her an additional $25 per month. Ophira currently pays $815 per year for insurance. How much will she pay next year?
$1149.15
$1672.15
$1449.00
$1449.15
Answer:
$1449.15
Step-by-step explanation:
currently paying 815
to pay next year: 41% increase + 25 extra per month
⇒ 141%·815 + 12·25
= 1149.15 + 300
= 1449.15
Can someone please explain this to me please?
Will give brainly if you actually answer the question
Answer:
Step-by-step explanation:
24)
3x - 10 > 2
3x - 10 + 10 > 2 + 10
3x > 12
3x/3 > 12/3
x > 4
5x - 15 < -5
5x - 15 + 15 < -5 + 15
5x < 10
5x/5 < 10/5
x < 2
B) x > 4 or x < 2
25) 1.5/60 = 12/x
x = 12(60) / 1.5
x = 480
B) 480 miles
This distance from Old Faithful to Mammoth Hot Springs is actually about 52 miles by road, so there must have been MASSIVE number of road closures to get this result...or else their scale is incorrect. 1.5 inch to 6.0 miles would be a much more accurate scale making the distance 48 miles.