In this problem, x = c1 cos t + c2 sin t is a two-parameter family of solutions of the second-order DE x'' + x = 0. Find a solution of the second-order IVP consisting of this differential equation and the given initial conditions. x(π/4) = 2 2 , x'(π/4) = 0

Answers

Answer 1

Differentiate the given solution:

[tex]x=C_1\cos(t)+C_2\sin(t) \implies x'=-C_1\sin(t)+C_2\cos(t)[/tex]

Now, given that x (π/4) = √2/2 … (I'm assuming there are symbols missing somewhere) … you have

[tex]\dfrac{\sqrt2}2=C_1\cos\left(\dfrac\pi4\right)+C_2\sin\left(\dfrac\pi4\right)[/tex]

[tex]\implies\dfrac1{\sqrt2} = \dfrac{C_1}{\sqrt2}+\dfrac{C_2}{\sqrt2}[/tex]

[tex]\implies C_1+C_2=1[/tex]

Similarly, given that x' (p/4) = 0, you have

[tex]0=-C_1\sin\left(\dfrac\pi4\right)+C_2\cos\left(\dfrac\pi4\right)[/tex]

[tex]\implies 0=-\dfrac{C_1}{\sqrt2}+\dfrac{C_2}{\sqrt2}[/tex]

[tex]\implies C_1=C_2[/tex]

From this result, it follows that

[tex]C_1+C_2=2C_1=1 \implies C_1=C_2=\dfrac12[/tex]

So the particular solution to the DE that satisfies the given conditions is

[tex]\boxed{x=\dfrac12\cos(t)+\dfrac12\sin(t)}[/tex]


Related Questions

Người ta chiếu xạ liều 3000 Rơn ghen vào một quần thể ruồi dấm ở thế hệ F1: Chiếu xạ 1000 con ruồi dấm không cho ăn đường thì có 80 con bị đột biến và chiếu xạ 1000 con ruồi dấm có cho ăn đường thì có 120 con bị đột biến. Cho ăn đường có ảnh hưởng đến tỉ lệ đột biến của ruồi giấm không, với mức ý nghĩa 5%? Giá trị kiểm định là

Answers

Answer:

gggggggggggggggggggggrrrrrrrrrrrttyuuiiiii

The table below shows some inputs and outputs of the invertible function f with domain all real numbers.

Answers

Answer:

f^-1 (-15) = -6

f^-1(4) + f(9)  = 0

Step-by-step explanation:

f^-1 (-15) =

Look where the output is -15 and  find the x value ( x=-6)

Since where are using the inverse function, the input becomes the output and  the output  and the output becomes the input

f^-1 (-15) = -6

f^-1 (4) = -11  (inverse function)

f(9) = 11  ( regular function)

f^-1(4) + f(9) = -11+11 = 0

After how many years, to the nearest whole year, will an investment of $100,000 compounded quarterly at 4% be worth
$213,022?
Provide your answer below:

Answers

9514 1404 393

Answer:

  19 years

Step-by-step explanation:

The compound interest formula tells you the future value of principal P invested at annual rate r compounded n times per year for t years is ...

  A = P(1 +r/n)^(nt)

Solving for t, we get ...

  t = log(A/P)/(n·log(1 +r/n))

Using the given values, we find t to be ...

  t = log(2.13022)/(4·log(1 +0.04/4)) ≈ 19.000

The investment will be worth $213,022 after 19 years.

five brothers of 4, 9, 11, 13 and 16 years respectively, receive an inheritance of 1,500,000, the will stipulated that that amount must be shared by the heirs so that, placed the shares in a bank, they would result in equal capitalized amounts, when each one reached 21, could raise his share. Knowing that the bank charges an interest rate of 9% per year, what is the amount of each share?

Answers

9514 1404 393

Answer:

Youngest to oldest:

160,406.86246,805.83293,230.01348,386.58451,170.72

Step-by-step explanation:

At 9% interest per year, the present value of 1 at age 20 is ...

  p(a) = 1.09^(a-20)

Adding the present values for the different ages, we get a total of about 2.35528984846. Dividing the inheritance by that amount gives the multiplier for each of the present value numbers. The result is the list of shares shown above. At age 20, each brother will inherit about 636,864.29.

__

Additional comment

This is the sort of question that suggests the use of a graphing calculator or spreadsheet for doing the tedious number crunching.

(We assume the bank pays 9% per year, rather than charges 9% per year.)

You measure 49 turtles' weights, and find they have a mean weight of 80 ounces. Assume the population standard deviation is 6.1 ounces. Based on this, construct a 99% confidence interval for the true population mean turtle weight. Round your answers to 2 decimal places.

Answers

Answer:

The 99% confidence interval for the true population mean turtle weight is between 77.76 and 82.24 ounces.

Step-by-step explanation:

We have 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 - 0.99}{2} = 0.005[/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 p-value of [tex]1 - 0.005 = 0.995[/tex], so Z = 2.575.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

[tex]M = 2.575\frac{6.1}{\sqrt{49}} = 2.24[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 80 - 2.24 = 77.76 ounces.

The upper end of the interval is the sample mean added to M. So it is 80 + 2.24 = 82.24 ounces.

The 99% confidence interval for the true population mean turtle weight is between 77.76 and 82.24 ounces.

Write each word phrase as an algebrale
expression for exercises 66-69
66) ten less than a number
67) the product of x andy
The algebraic expression for ten less than n

Answers

66) ten less than a number

Let the number be n

= n - 10

67) the product of x and y

= x × y or xy

68) The algebraic expression for ten less than n

= n - 10

Must click thanks and mark brainliest

What is the order of rotational symmetry for the figure?
A. 3
B. 2
C. 4 or more
D. 1

Answers

9514 1404 393

Answer:

  C.  4 or more

Step-by-step explanation:

Rotating the figure in increments of 90° will give the same figure. There are 4 such rotations in a full turn. The order of rotational symmetry is 4.

Find the area of the triangle with vertices (0,0,0),(−4,1,−2), and (−4,2,−3).

Answers

Answer:

0.5*sqrt33

Step-by-step explanation:

A(0,0,0) B(-4,1,-2), c(-4,2,-3)

Vector AB is (-4-0,-1-0, -2-0)= (-4,-1,-2)  The modul of AB is sqrt (4squared+

+(-1) squared+ (-2) squared)= sqrt (16+1+4)=sqrt21

Vector AC is (-4,2,-3) The modul of vector AC is equal to sqrt ((-4)squared+ 2squared+(-3)squared)= sqrt(16+4+9)= sqrt29

Vector BC is equal to (-4-(-4), 2-1, -3-(-2))= (0,1,-1)

The modul of BC is sqrt (1^2+(-1)^2)=sqrt2

Find the angle B

Ac^2= BC^2+AB^2-2*BC*AB*cosB

29= 2+21-2*sqrt2*sqrt21*cosB

29= 2+21-2*sqrt42*cosB

cosB= -3/ sqrt42

sinB= sqrt( 1-(-3/sqrt42)^2)=sqrt33/42= sqrt11/14

s=1/2* (sqrt2*sqrt21*sqrt11/14)=1/2*sqrt(42*11/14)= 0.5*sqrt33

please help me

find x​

Answers

9514 1404 393

Answer:

  x = 6√2

Step-by-step explanation:

The side ratios in an isosceles right triangle are ...

  1 : 1 : √2

These will be the same as ...

  x : x : 12

so, ...

  x = 12/√2

  x = 6√2

Question 6 of 10
The domain of a function f(x) is x = 0, and the range is ys -1. What are the
domain and range of its inverse function, '(x)?

Answers

Answer: y = 0 and x = -1

Select the correct answers in the table.
Rachel enjoys exercising outdoors. Today she walked 5 2/3 miles in 2 2/3 hours. What is Rachel’s unit walking rate in miles per hour and in hours per mile?

Answers

Rachel enjoys exercising outdoors. Today she walked 5 2/3 miles in 2 2/3 hours. What is Rachel's unit walking rate in miles per hour and in hours per miles? 5 2/3 / 2 2/3 = 17/3 / 8/3 = 17/3 x 3/8 = 17/8 = 2 1/8 miles per hour.

Give example to verify if the given statement is true or false
1) if two numbers are co-primes , at least one of them should be prime number.

Answers

Answer:

no

Step-by-step explanation:

if two numbers are co-prime that is not necessary that one of them must be a prime number

If x/4-y/6=1/6 and y/z=1/2, then what is the value of 3x-z?
A. 4
B.6
C. 3
D. 2
E. None​

Answers

Answer:
D. 2
Explanation

Factors and rewrite the expression 25x-15​

Answers

Answer:

5(5x-3)

Step-by-step explanation:

The common factor in this expression is 5 so divide 5 to all the values

25/5=5

-15/5= -3

Put these values into parenthesis and leave the 5 on the left side and out of the parenthesis

5(5x-3)

Answer:

5(5x - 3)

Step-by-step explanation:

The greatest common factor here is 5. Divide each term by 5 and simplify.

25x/5 = 5x

15/5 = 3

Therefore, the answer is 5(5x - 3).

Please help explanation if possible

Answers

Answer:

18.84 feet.  let me know if you have ay other questions.

Step-by-step explanation:

The way to find the formula for circumference is kinda complicated so it is best to ust memorize the formula, which is 2πr.  or 2 times pi times the radius.  

Your problem gives you the formula, but instead of 2 and r in it you have d, which is the diameter.

The diameter of the circle is 2 times the radius, so that's why it is replaced.

the radius is the distance from the center fo the circle to one edge, and the diameter is the distance through the circle passing through its center.  so it's the center to one end plus the center to another end.  or r+r which is also 2r.

So d = 2r, so in this problem d =6 feet.

So now the formula πd = 3.14*6 feet = 18.84 feet

express the following in standard form
1) 5,94,00,00,00,000

2) 6892.25
Plz tell​

Answers

Answer:

first one is going to be

5.94x10¹¹

second one is going to be

6.89225x10³

HELPP plz don't send a file whats the answer and explanation plz if you can

Answers

Answer:

5/0 is not a rational number

Step-by-step explanation:

you cant divide by 0

Find the local linear approximation L(x) of the function f(x) = 5−x^2 at x = 2.
Use this to estimate f(2.1).

Answers

Answer:

L(x)=-4x+9

L(2.1)=0.6

Step-by-step explanation:

It's asking us to find the tangent line to curve f(x) = 5−x^2 at x = 2.

Theb use this to estimate f(2.1).

To find slope of tangent line, we must differentiate and then plug in 2 for x.

f'(x)=0-2x by constant and power rule.

f'(x)=-2x

So the slope of the tangent line is -2(2)=-4.

A point on this tangent line shared by the curve is at x=2. We can find it's corresponding y-value using f(x)=5-x^2.

f(2)=5-(2)^2

f(2)=5-4

f(2)=1

So let's rephrase the question a little.

What's the equation for a line with slope -4 and goes through point (2,1).

Point-slope form y-y1=m(x-x1) where m is slope and (x1,y1) is a point on the line.

Plug in our information: y-1=-4(x-2).

Distribute: y-1=-4x+8

Add 1 on both sides: y=-4x+9

Let's call this equation L(x), an expression to approximate value for f near x=2.

L(x)=-4x+9

Now the appropriation at x=2.1:

L(2.1)=-4(2.1)+9

L(2.1)=-8.4+9

L(2.1)=0.6

If we did plug in 2.1 into given function we get 5-(2.1)^2=0.59 . This is pretty close to our approximation above.

Use differentials to estimate the amount of paint needed to apply a coat of paint 0.07 cm thick to a hemispherical dome with diameter 50 m. (Round your answer to two decimal places.)

Answers

Answer:

2.75 m²  

Step-by-step explanation:

From the information given:

the thickness of the paint = 0.07 cm = (0.07/100) m

= 0.0007 m thick

the diameter hemispherical dome = 50 m

radius of the dome = 50m /2 = 25 m

The volume of a hemispherical dome is expressed as:

[tex]V = \dfrac{2}{3}\pi r^3[/tex]

Thus, the change in the volume now is:

[tex]\dfrac{dV}{dr} = \dfrac{2}{3}\pi *3 r^2[/tex]

[tex]{dV} = \dfrac{2}{3}\pi *3 r^2 (dr)[/tex]

[tex]{dV} = 2 \pi r^2 (dr)[/tex]

dV = 2π × (25)² (0.0007)

where;

dr = 0.0007

dV = 2π × (25)² (0.0007)

dV = 2.75 m²  

Ms. Lowder has 2 children, one in first grade and one in fifth grade. Both children need paper for school. Paper costs $2.29 per pack. If the first grader needs 2 packs of paper and the fifth grader needs 6 packs of paper, how much money will Ms. Lowder spend on paper?

Answers

2packs +6 packs=8packs$2.29×8=$18.32

the answer is she spend $18.32

1% defective parts. 100,00 parts made in total. The number of defects made should equal?

Answers

Answer:

1,000 defects

Step-by-step explanation:

Find how many defects that should be made by finding 1% of 100,000:

100,000(0.01)

= 1000

So, there should be 1,000 defects

What is the area of a square with a side length of 32 yards?

Answers

Answer:

A=1024 yd.^2

Step-by-step explanation:

A=s^2

Substitute,

A=32^2

So,

A=1024 yd.^2

Answer:

1024 yd²

Step-by-step explanation:

Since it's a square, the side lengths will all be the same length. Due to this, you can square the given value to find the area.

A(Square) = 32² = 1024

Dad is twice as old as Junior. Gramps is twice as old as Dad. The sum of the three ages is 140. How old is Gramps?​

Answers

Answer:

80

Step-by-step explanation:

We can start of with Junior's age. Then if dad is twice as old as Junior, then we add 2 parts and get 3 parts. Then Gramps is twice as old as Dad so we add 4 parts and get 7 parts. Now we divided 140 by 7. We get 20. This is Junior's age. By looking at that, we know Dad is 40, and Gramps is 80.

Gramps is 80 years old.

Hi! I'm happy to help!

We can say that Junior is x years old. This would mean that Dad is 2x years old, and Gramps is 4x years old. All together, their age is 7x. We can write an equation to solve.

7x=140

Divide both sides by 7 to find out x.

x=20

This means that Junior is 20 years old. Dad is double that, so he is 40 years old. And Gramps is double that so he is 80 years old.

To check our answer we can add all of them together.

20+40+80

140

This means that Gramps is 80 years old.

I hope this was helpful, keep learning! :D

Consider the given statement. Determine whether its is equivalent to the given statement, a negation, or neither. Attached is the photo reference.

Answers

Answer:

1. Negation

2. Equivalent

3. Neither

4. Neither

Step-by-step explanation:

p ^ ~q

~q → p~

~q ∨ p

~p ∨q

accountancy

So i have to make trial balance and im kinda confused with 'interest'. So which side did it go to? Credit or debit? It didn't state the interest as received or expense/paid. someone told me to look at the bank but hey i need more explanation T^T​​

Answers

You would do credit because debit is not the one

Find x. Round your answer to the nearest tenth of a degree.

Answers

Answer:

x = 55.8

Step-by-step explanation:

Since this is a right triangle, we can use trig functions

cos theta = adj / hypotenuse

cos x = 9/16

Taking the inverse cos of each side

cos^-1 (cos x) = cos^-1 (9/16)

x=55.77113

To the nearest tenth

x = 55.8

Answer:

Relative to x, the side of 16 is the hypotenuse, and the side of 9 is adjacent.

So we think, what trigonometric property relates hypotenuse and adjacent sides of a right triangle?

SOH CAH TOA

We can use the COSINE function to solve in this case, as we have both  the ADJACENT SIDE (A) and the HYPOTENUSE (H).

Cosine = Adjacent/Hypotenuse

Cosine (x) = 9/16

Angle x = 55.8 degrees.

Let me know if this helps!

A popular beach erodes 4 inches per year on average.

An eroding beach.
A. How many years will it take for the coastline to erode one foot?

Answers

Answer:

3 years

Step-by-step explanation:

4 inches per year on average

1 foot = 12 inches

12 divided by 4 equals 3

therefore it is 3 years


(5, 4)
11-5-2)
16.nat's the slope-intercept form of the equation of the line graphed in this figure?
O A. y = 5/3x + 1
O B.y=-3x + 1
O C. y = 3x + 1
O D.y = -5/3X - 1

Answers

Answer:

The answer is B. y=3/5x+1

The​ half-life of a radioactive substance is 20 years. If you start with some amount of this​ substance, what fraction will remain in 180 years?

Answers

Answer:

1/512

Step-by-step explanation:

Let staring fraction = x

Half-life = 20 years ; this is the time taken for an element to decrease to half of its original size

Hence,

After 20 years - - - > x/2

After 40 years - - - - > x/2 ÷ 2 = x/2 * 1/2 = x /4

After 60 years - - - - > x/4 ÷ 2 = x/4 * 1/2 = x/8

After 80 years - - - - -> x/8 ÷ 2 = x/8 * 1/2 = x / 16

After 100 years - - - > x/16 * 1/2 = x/32

After 120 years - - - - > x/32 * 1/2 = x/64

After 140 years - - - - -> x / 64 * 1/2 = x / 128

After 160 years - - - - - > x / 128 * 1/2 = x/256

After 180 years - - - - > x/256 * 1/2 = x / 512

Hence, the fraction after 180 years = 1/512

Find the surface area of the figure round your answer to the nearest tenth if necessary

Answers

Answer:

.kpokojj8nvchrfhuthuvu9jeuvh

Step-by-step explanation:

j8tguhrhfgzhedh8ugh8euweuhujdhhruehf hhcufe7fhd fu y in my as 08ygrt8hthts8hewhrs8h8h8

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