giải phương trình y′′ − 7y′ + 6y = sin x.

Answers

Answer 1

Start with the underlying homogeneous equation:

[tex]y''-7y'+6y=0[/tex]

which has characteristic equation

[tex]r^2-7r+6=(r-6)(r-1)=0[/tex]

with roots at r = 6 and r = 1. So the characteristic solution is

[tex]y_c=C_1e^{6x}+C_2e^x[/tex]

Now for the particular solution, we can use the method of undetermined coefficients, with the following ansatz (the "guess" solution) and its derivatives,

[tex]y_p=a\cos x+b\sin x[/tex]

[tex]{y_p}'=-a\sin x+b\cos x[/tex]

[tex]{y_p}''=-a\cos x-b\sin x[/tex]

Substituting these into the original equation gives

[tex](-a\cos x-b\sin x)-7(-a\sin x+b\cos x)+6(a\cos x+b\sin x)=\sin x[/tex]

[tex](5a-7b)\cos x+(7a+5b)\sin x=\sin x[/tex]

[tex]\implies\begin{cases}5a-7b=0\\7a+5b=1\end{cases}\implies a=\dfrac7{74},b=\dfrac5{74}[/tex]

So the particular solution is

[tex]y_p=\dfrac7{74}\cos x+\dfrac5{74}\sin x[/tex]

and hence the general solution is

[tex]y=y_c+y+p=\boxed{C_1e^{6x}+C_2e^x+\dfrac7{74}\cos x+\dfrac5{74}\sin x}[/tex]


Related Questions

równanie zmiany prędkość autokaru poruszającego się po prostym odcinku szosy i rozpoczynającego hamowanie od szybkości 20m/s ma postać v(t)=25-5t. Korzystając z rachunku całkowego wyznacz drogę hamowania autokaru.

Answers

Answer:

s = 22.5 m

Step-by-step explanation:

the equation for the speed change of a coach moving along a straight section of the road and starting braking at a speed of 20 m / s has the form v (t) = 25-5t. Using integral calculus, determine the coach's braking distance.

v (t) = 25 - 5 t

at t = 0 , v = 20 m/s

Let the distance is s.

[tex]s =\int v(t) dt\\\\s =\int (25 - 5t)dt\\\\s= 25 t - 2.5 t^2 \\[/tex]

Let at t = t, the v = 20

So,

20 = 25 - 5 t

t = 1 s

So, s = 25 x 1 - 2.5 x 1 = 22.5 m

How do I do this and what’s the answers?

Answers

Answer:

a.5years=300 rabbits

b. 50 years(multiply 50 by 300)

Step-by-step explanation:

hope this is helpful

the high temperature is forecast to be 5.4 F . What is this temperature in degrees Celsius ()?

Answers

Answer:

-14c

Step-by-step explanation:

I’m using the actual values 1F = -17C so just times that by 5.4

Find the population variance and standard deviation.
8​, 17​, 29​, 35​, 41

Answers

Answer:

53

Step-by-step explanation:

By taking the number "41" and minus it with "35" and you'll get 12. Take the number "12" and plus with "41" and you'll get the answer.

the population variance is 144 and the population standard deviation is 12.

To find the population variance and standard deviation for the given data set, follow these steps:

Step 1: Find the mean (average) of the data set.

Step 2: Subtract the mean from each data point to find the differences.

Step 3: Square each difference.

Step 4: Calculate the sum of the squared differences.

Step 5: Divide the sum of squared differences by the total number of data points to find the variance.

Step 6: Take the square root of the variance to find the standard deviation.

Given data set: 8, 17, 29, 35, 41

Step 1: Find the mean (average):

Mean = (8 + 17 + 29 + 35 + 41) / 5

Mean = 130 / 5

Mean = 26

Step 2: Find the differences from the mean:

Differences: (8 - 26) = -18, (17 - 26) = -9, (29 - 26) = 3, (35 - 26) = 9, (41 - 26) = 15

Step 3: Square each difference:

Squared differences: [tex](-18)^2 = 324, (-9)^2 = 81, 3^2 = 9, 9^2 = 81, 15^2 = 225[/tex]

Step 4: Calculate the sum of squared differences:

Sum of squared differences = 324 + 81 + 9 + 81 + 225 = 720

Step 5: Calculate the variance:

Variance = Sum of squared differences / Number of data points

Variance = 720 / 5

Variance = 144

Step 6: Calculate the standard deviation:

Standard deviation = √Variance

Standard deviation = √144

Standard deviation = 12

So, the population variance is 144 and the population standard deviation is 12.

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I'll give brainliest if you answer 11 and 12

Answers

Answer:

tanx=30/27

tanx=10/9

x=48

To paint interior​ walls, a person charges 50¢ per square foot plus the cost of the paint. For a recent​ job, the paint cost ​$100 and the total bill was ​$475.
The person must have painted ____ ft^2.

Answers

Answer:

750 ft²

Step-by-step explanation:

.Given :

Charge per ft² = 50¢ = $0.5

Total cost = ((charge per ft² * number of ft²) + cost of paint)

Given that :

Paint cost = $100

Total cost = $475

Number of ft² = x

Plugging values into the equation :

475 = (( 0.5 * x) + 100)

475 = 0.5x + 100

475 - 100 = 0.5x

375 = 0.5x

x = 375 / 0.5

x = 750 ft²

Debra bought 16 pounds of sugar for $7.
How many dollars did she pay per pound of sugar

Answers

She paid .43¢ or .44¢for each pound

A television is purchased by a company for $210. They mark up the price by 55%. What is the selling price? Show two different ways to solve this problem.​

Answers

Answer:

$325.50, mentioned methods below.

Step-by-step explanation:

55% means it increases by 55%.  an increase of 50% is basically taking half of the original amount .  So a 50% increase of 4 would be 4 + .5*4 = 4+2 = 6

So for 210 that's 210 + .55*210 = 325.50

You could also factor to make it a little simpler.

210 + .55*210 = 325.50

210(1 + .55) = 325.50

210*1.55 = 325.50

.55 = 55/100 = 11/20

Select the correct answer.

The parent tangent function is horizontally compressed by a factor of 1/2 and reflected over the x-axis. Which equation could represent function g

the result of this transformation?

Answers

Answer:

[tex]g(x) = -\frac{1}{2}\tan{x}[/tex]

Step-by-step explanation:

Tangent function:

The tangent function is:

[tex]f(x) = \tan{x}[/tex]

Horizontally compressed by a factor of 1/2

Horizontally compressing by a factor of 1/2 is multiplying by 1/2. So

[tex]g(x) = \frac{1}{2}\tan{x}[/tex]

Reflected over the x-axis.

Reflecting a function over the x-axis is the same as multiplying it by -1. Then g is given by:

[tex]g(x) = -\frac{1}{2}\tan{x}[/tex]

Which system of linear inequalities is represented by
the graph?
+
oyz_x+3 and 3x – y> 2
o ye}x+3 and 3x –y> 2
o y }x+3 and 3x + y> 2
O ya 4x+3 and 2x-y> 2

Answers

Answer:

o ye}x+3 and 3x –y> 2 system of linear inequalities is represented by the graph.

PLEASE LET ME KNOW IF ¡ AM WRONG!

The system of linear inequalities represented by the graph is

y ≥ (1/3)x + 3 and 3x - y  > 2

Option A is the correct answer.

What is inequality?

It shows a relationship between two numbers or two expressions.

There are commonly used four inequalities:

Less than = <

Greater than = >

Less than and equal =≤

Greater than and equal = ≥

We have,

We see that,

When we graph,

y ≥ (1/3)x + 3 and 3x - y  > 2 we get the graph shown.

y ≥ (1/3)x + 3

This inequality is positive on the y-axis.

3x - y  > 2

3x > 2 + y

This inequality is positive on the x-axis.

Thus,

The system of linear inequalities represented by the graph is

y ≥ (1/3)x + 3 and 3x - y  > 2

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Complete the expressions.
Write each answer as a number, a variable, or the product of a number and a variable.
=7r6
=
7r
Commutative property of multiplication
=
Multiply

Answers

Complete question :

Complete the expressions Write each answer as a number, a variable, or the product of a number and a variable 7(9r + 2) = 7 . 9r + 7 . ___ = ___ +

Answer:

2 ; 63r ; 14

Step-by-step explanation:

Given :

7(9r + 2)

Opening the bracket :

7*9r + 7*2 - - - - (1)

Taking the product

63r + 14 - - - - (2)

Now filling the blanks :

First blank corresponds to 2 (from (1))

Second blank corresponds to 63r (from (2))

Third blank should be 14

Find y.
Round to the nearest tenth:
28°
х
350 ft
y
y = [? ]ft

Answers

Answer:

y = 658.3 ft

Step-by-step explanation:

Alternate angles are equal. Therefore,

Reference angle (θ) = 28°

Length of side Opposite to reference angle = 350 ft

Adjacent side = y

Apply TOA, which is:

Tan θ = Opp,/Adj

Substitute

Tan 28 = 350/y

y*tan 28 = 350

y = 350/tan 28

y = 658.3 ft (nearest tenth)

reduce 5/10 to it's smallest fraction​

Answers

Answer:

1/2

If you divide both numbers by 5, you would get 1/2

Answer : 1/2

Both the numerator and the denominator have the greatest common factor of 5. You can divided both the top and bottom by 5, giving you 1/2.

Express the terms of the following sequence by giving an explicit formula. 5 , 2 , -1 , -4, -7 , .

Answers

Answer:

Step-by-step explanation:

a1=5

d=2-5=-3

[tex]a_{n}=5+(n-1)(3)\\a_{n}=5+3n-3\\a_{n}=3n+2[/tex]

A=12 because I did the test and got it right and ask me for help if needed

the probabilities that Kojo and Adwoa will pass an examination are 3/4 and 3/5 respectively. Find the probability that both will fail the examination​

Answers

Assuming that their exam success is independent then
P(both fail) = 1/4 x 2/5 = 2/20 or 1/10

Which expression is equivalent to
3V64k^12

Answers

Answer:

I think the answer is C

Step-by-step explanation:

Your friend was supposed to repay a loan with a loan payment of $1,000 due in 6 months and another loan payment of $1,500 due in 4 years. However, your friend agrees to make two payments that replace the originally scheduled payments. The first replacement payment of $1,250 is due in 2 years and the second replacement payment of $X is due in 3 years. Suppose the interest is 7% p.a. compounded quarterly and the focal date is 3 years from now (Year 3), your friend asks for your help to determine the size of the second replacement payment, $X. Answer the following question:

Your answer for $X at the focal date is ($BLANK)
. (Express in 2 decimals) Hint: Based on your answer in Q3 and the replacement payment in Q5, you will need to determine $X.

Note: to receive the full mark, you will use all the decimal places when performing calculations, round to 2 decimal places in your final answer, and there is no need to include other symbols such as $ and comma in your final answer.

Answers

okay okay thank you thank youuu thank you thank youu thank you thank youuu thank you thank youu thank you thank youuu thank

Ana vende productos de limpieza .Por cada $100 que venda le dan de comisión $30 .¿Cuánto ganará si vende $600?

Answers

Answer:

$180

Step-by-step explanation:

$600/$100 = 6

$600 es 6 veces $100.

Por vender $600 gana 6 veces mas que por vender $100.

6 * $30 = $180

Respuesta: $180

Which of the suggestions do NOT rely on the support of a parent or guardian?

Answers

what are the suggestions?

Answer:

what are the options

Step-by-step explanation:

A. 3.9

B. 1.0

C. 1.7

D 3.3

Answers

Answer:

its for sure C

Step-by-step explanation:

Find the value of x and show work

Answers

Answer:

20

Step-by-step explanation:

Solve the inequality –8 < x – 14.

Answers

Answer:

x=6

Step-by-step explanation:

Answer:

Interval Notation:

(6,∞)

Inequality Form:

x>6

there ya go

please help me with the steps thx
find the area

Answers

Answer:

D) [tex]222[/tex] [tex]km^2[/tex]

Step-by-step explanation:

------------------------------

Let's find the surface area of the rectangular prism.

Multiply 7 times 9 for the front side and 7 times 9 again for the back side.

[tex]7*9=63[/tex]

[tex]7*9=63[/tex]

---------->>>>

Multiply 7 times 3 for the left side and 7 times 3 again for the right side.

[tex]7*3=21[/tex]

[tex]7*3=21[/tex]

---------->>>>

Multiply 3 times 9 for the top side and again for the bottom side.

[tex]3*9=27[/tex]

[tex]3*9=27[/tex]

---------->>>>

Now, let's add all these sums.

[tex]63+63+21+21+27+27=[/tex]

[tex]126+42+54=[/tex]

[tex]168+54=[/tex]

[tex]=222[/tex]

------------------------------

Hope this is helpful.

1. If f(x)=4*, then which of the following is the value of f(-2)?

Answers

Answer:

what is the following

Step-by-step explanation:

2x+5x=? hihihihihiihihihihihihihihihi

Answers

Answer:

7x

Step-by-step explanation:

its simple you just add them

Solve each question (a, b, c) and show your work. Thank you <3

Answers

Answer:

a) 112 ft.

b) 256 ft. and 3 seconds

c) 7 seconds

Step-by-step explanation:

a) The model rocket is lauched from a platform. To find the height of the platform, we need to find h when t = 0, because the rocket starts from the platform when no time has elapsed:

[tex]h=-16t^2+96t+112[/tex]

[tex]h=-16*0+96+0+112\\\\h=112[/tex]

Therefore, the height of the platform is [tex]\fbox{112}[/tex] ft.

b) If you learned calculus before, we can find the maximum height easily. We take the derivative of h and set it equal to 0. Remember, the derivative of a function is simply the slope of it at an instantaneous point. At the maximum point of a function, it's slope equals to 0.

[tex]h=-16t^2+96t+112\\h'=-32t+96+0\\h'=-32t+96[/tex]

Ok! Let's set the derivative of h to 0!

[tex]0=-32t+96\\-96=-32t\\t=3[/tex]

We now know how long it takes for the rocket to reach maximum point (t represents seconds), but we also need to find the maximum height. We can simply plug our t=3 into the function of h, because t=3 is the point where the rocket reaches maximum height:

[tex]h(3)=-16(3)^2+96*3+112\\h(3)=-144+288+112\\h(3)=256[/tex]

The maximum height of the rocket is [tex]\fbox{256}[/tex] ft and the rocket takes [tex]\fbox{3}[/tex] seconds to reach the height.

c) The rocket reaches the ground when h equals 0. We can set up the equation to solve for it:

[tex]h=-16t^2+96t+112\\0=-16t^2+96t+112\\0=-16(t+1)(t-7)\\0=(t+1)(t-7)\\t=-1, t=7[/tex]

However, time can never be negative.

Therefore, it takes the rocket [tex]\fbox{7}[/tex] seconds to reach the ground.

I hope this helps! Let me know if you have any questions :)

solve the inequality |x + 4| < |2x|

Answers

Answer:

Below in bold.

Step-by-step explanation:

One way to do these is to square both sides:

(x + 4)^2 < 4x^2

x^2 + 8x + 16 < 4x^2

3x^2 - 8x - 16 > 0

Let this = 0:

3x^2 - 8x - 16 = 0

(3x + 4)(x - 4) = 0

x = -4/3, 4.

So the critical  points are -4/3 and 4.

Make a table:

                      x < - 4/3           -4/3 +< x  <= 4            x > 4

3x + 4                  <0                        > 0                        > 0

x - 4                     <0                        < 0                       > 0

(3x+4)(x-4)           >0                        <0                         > 0

So the solution is   x < -4/3 or x > 4

or in  interval notation:

(-∞, -4/3) U (4, ∞)

Answer:

See image below for answer:)

Step-by-step explanation:

FYI you can use the app photo math, you just take a pic of the problem and it gives you the answer and explains the steps and it is free.

Perform the indicated operation.
(7 - 11) + (-3+51

Answers

Step-by-step explanation:

(7-11)+(-3+51)

(-4)+(48)

44 ans

Answer:

44

Step-by-step explanation:

7-11= -4

-3+51=48

-4+48=44

Cory is building an enclosure with recycled cardboard for her collection of model cars. Her design is as shown below: What is the length of side EF in inches?
a 45
b 25
c 15
d 30

Answers

Answer:

25

Step-by-step explanation:

The length of side EF in Cory's project is 25 inches. Thus, the correct answer is option b.

To determine the length of side EF in Cory's project, we can use the concept of proportionality between corresponding lengths in Cory's design and project.

We are given that the length ML in Cory's design corresponds to the length DC in Cory's project, and ML is 8 inches while DC is 40 inches. Using this information, we can set up the proportion:

ML / DC = NH / EF

Plugging in the known values, we have:

8 / 40 = 5 / EF

To solve for EF, we can cross-multiply:

8 * EF = 40 * 5

8EF = 200

Dividing both sides by 8:

EF = 200 / 8

EF = 25

Therefore, the length of side EF in Cory's project is 25 inches.

Thus, the correct answer is option b: 25 inches.

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in circle T with m angle STU=50 and ST=3 units, find the length of arc SU. Round to the nearest hundredth.

Answers

9514 1404 393

Answer:

  arc SU ≈ 2.62 . . . units

Step-by-step explanation:

The arc length is given by ...

  s = rθ

where r is the radius, and θ is the central angle in radians.

  arc SU = ST·STU = 3·(50°·π/180°) = 5π/6

  arc SU ≈ 2.62 . . . units

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