I NEED HELP PLEASE!!!

Answer:

y"-6y'+18y=0

Second order

Step-by-step explanation:

Since there are 2 constants, the order of the differential equation will be 2. This means we will need to differentiate twice.

y = e^(3x) (acos3x +bsin3x)​

y'=3e^(3x) (acos3x+bsin3x)

+e^(3x) (-3asin3x+3bcos3x)

Simplifying a bit by reordering and regrouping:

y'=e^(3x) cos3x (3a+3b)+e^(3x) sin3x (3b-3a)

y"=

3e^(3x) cos3x (3a+3b)+-3e^(3x) sin(3x) (3a+3b)

+3e^(3x) sin3x (3b-3a)+3e^(3x) cos(3x) (3b-3a)

Simplifying a bit by reordering and regrouping:

y"=

e^(3x) cos3x (9a+9b+9b-9a)

+e^(3x) sin3x (-9a-9b+9b-9a)

Combining like terms:

y"=

e^(3x) cos3x (18b)

+e^(3x) sin3x (-18a)

Let's reorder y like we did y' and y".

y = e^(3x) (acos3x +bsin3x)

y=e^(3x) cos3x (a) + e^(3x) sin3x (b)

Objective is to find a way to combine or combine constant multiples of y, y', and y" so that a and b are not appearing.

Let's start with the highest order derivative and work down

y"=

e^(3x) cos3x (18b)

+e^(3x) sin3x (-18a)

We need to get rid of the 18b and 18a.

This is what we had for y':

y'=e^(3x) cos3x (3a+3b)+e^(3x) sin3x (3b-3a)

Multiplying this by -6 would get rid of the 18b and 18a in y" if we add them.

So we have y"-6y'=

e^(3x) cos3x (-18a)+e^(3x) sin3x (-18b)

Now multiplying

y=e^(3x) cos3x (a) + e^(3x) sin3x (b)

by 18 and then adding that result to the y"-6y' will eliminate the -18a and -18b

y"-6y'+18y=0

Also the characteristic equation is:

r^2-6r+18=0

This can be solved with completing square or quadratic formula.

I will do completing the square:

r^2-6r+18=0

Subtract 9 on both sides:

r^2-6r+9=-9

Factor left side:

(r-3)^2=-9

Take square root of both sides:

r-3=-3i or r-3=3i

Add 3 on both sides for each:

r=3-3i or r=3+3i

This confirms our solution.

Another way to think about the problem:

Any differential equation whose solution winds up in the form y=e^(px) (acos(qx)+bsin(qx)) will be second order and you can go to trying to figure out the quadratic to solve that leads to solution r=p +/- qi

Note: +/- means plus or minus

So we would be looking for a quadratic equation whose solution was r=3 ×/- 3i

Subtracting 3 on both sides gives:

r-3= +/- 3i

Squaring both sides gives:

(r-3)^2=-9

Applying the exponent on the binomial gives:

r^2-6r+9=-9

Adding 9 on both sides gives:

r^2-6r+18=0

9514 1404 393

Answer:

  B) f(1)=7, f(n+1)= f(n)-3; for n >= 1

Step-by-step explanation:

The first term of the sequence is 7 and the next (4) is found by adding -3 to that: 4 = 7-3. This is described in answer choice B.

Answer:

a pair of trousers cost = x = 195 $

one shirt costs = x - 50 = 145 $

Step-by-step explanation:

= 3x- 150

2 trousers and 3 shirts cost = 825

=> 2x + 3x - 150 = 825

=> 5x = 975

x = 195

a pair of trousers cost = x = 195 $

a pair of trousers cost = x = 195 $ one shirt costs = x - 50 = 145 $

Answer:36

Step-by-step explanation:

Answer:

im so confused

Step-by-step explanation:

Answer:

what is this goat saying

Answer:

228 feet

Step-by-step explanation:

Since M represents the number of lessons he completes,

sub M=8 into S=26M+20

S=26(8)+20

=228

Answer:

I think it is Obtuse.

Step-by-step explanation:

120 Degrees - Obtuse

Answer: 8

Hope this help :)

A fraction calcium pantothenate contains 0.5 gram of a tablet 5 tablets to make up 2.3 grams.

To calculate the amount of calcium pantothenate contained in a given number of tablets, use the given information that one tablet contains 0.5 grams.

Amount in n 2 1/4 tablets:

To calculate the amount of calcium pantothenate in n 2 1/4 tablets, we need to calculate the total amount for each part (whole tablets and the fraction of a tablet) and then sum them up.

Amount in n whole tablets: n tablets × 0.5 grams/tablet

Amount in 1/4 tablet: (1/4)× 0.5 grams

So, the total amount in n 2 1/4 tablets would be:

Total amount = n ×0.5 + (1/4) ×0.5 grams

Tablets needed to make up 2.3 grams:

To calculate the number of tablets needed to make up 2.3 grams of calcium pantothenate, set up a proportion using the given tablet amount (0.5 grams/tablet).

Let x be the number of tablets needed.

0.5 grams/tablet = 2.3 grams / x tablets

Cross-multiply:

0.5 × x = 2.3

x = 2.3 / 0.5

x = 4.6

To know more about fraction here

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Answer:

N = 50 +4d

Step-by-step explanation:

Take the original number of stamps and add the stamps per days times the number of days

N = 50 +4d

Answer:

Step-by-step explanation:

Given,

Radius = 30 in

So,

Circumference

[tex] = 2\pi r[/tex]

[tex] = 2 \times \pi \times 30in.[/tex]

[tex] = 60\pi \: in.(ans)[/tex]

[tex] \sf \: r \: = 30 \: in. \\ \sf \: C \: = 2\pi r \\ \\ \sf \: C \: = 2\pi(30) \\ \sf \: C = 2 \times 30\pi \\ \sf \: C = \boxed{\underline{ \bf c. \: 60\pi \: in.}}[/tex]

Answer:

1. purple graph

2. orange graph

3. green graph

4. blue graph

Answer:

[tex]x^{7}[/tex]

Step-by-step explanation:

When multiplying exponents, you add them together.

x^12

Step-by-step explanation:

x^5*x^7

x^5+7

=x^12

Answer:

19 bags of peanuts and 31 bags of pistachios were sold.

Step-by-step explanation:

This question is solved by a system of equations.

I am going to say that:

x is the number of bags of peanuts sold.

y is the number of bags of pistachios sold.

50 bags of  peanuts and pistachios were sold

This means that [tex]x + y = 50[/tex], that is: [tex]x = 50 - y[/tex]

A grocery store recently sold a  bag of peanuts for $0.76 and a bag of pistachios for $3.68. Were sold for a total of $128.52.

This means that:

[tex]0.76x + 3.68y = 128.52[/tex]

Since [tex]x = 50 - y[/tex]

[tex]0.76(50 - y) + 3.68y = 128.52[/tex]

[tex]2.92y = 90.5[/tex]

[tex]y = \frac{90.5}{2.92}[/tex]

[tex]y = 31[/tex]

[tex]x = 50 - y = 50 - 31 = 19[/tex]

19 bags of peanuts and 31 bags of pistachios were sold.

Answer:

(×:x is a natural number up to 10) just an example

Answer:

The Answer of the above question is 30.25

Step-by-step explanation:

Hope it helps you.

Answer:

try to calculate

here some examples

Step-by-step explanation:

Decimal Degrees to Degrees, Minutes, Seconds Calculator

Enter decimal degrees to convert to minutes and seconds. See the formulas below to see how it’s done.

Angle:

Decimal:

47.31

°

degrees, minutes, seconds to decimal

Degrees, Minutes, & Seconds:

47° 18′ 36″

I hope it helps

The equation of the graph is : x = -2

A graph is a pictorial representation of the locus of a certain point.

A graph can be drawn by picking some fixed points from the locus of the point.

Here, the straight line passes through the points are : (-2,1); (-2,2); (-2,-5);(-2,-5).

Hence, the straight line is to be parallel to the x-axis and the equation of the graph is x= -2.

Learn more about graph here :

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Answer:

a) The sample mean is of 49 and the sample standard deviation is of 11.7.

b) The range of the true mean at 90% confidence level is of 9.62 hours.

c) The prediction interval, at a 90% confidence level, of it's failure time is between 39.38 hours and 58.62 hours.

Step-by-step explanation:

Question a:

Sample mean:

[tex]\overline{x} = \frac{34+40+46+49+61+64}{6} = 49[/tex]

Sample standard deviation:

[tex]s = sqrt{\frac{(34-49)^2+(40-49)^2+(46-49)^2+(49-49)^2+(61-49)^2+(64-49)^2}{5}} = 11.7[/tex]

The sample mean is of 49 and the sample standard deviation is of 11.7.

b)Determine the range of the true mean at 90% confidence level.

We have to find the margin of error of the confidence interval. Since we have the standard deviation for the sample, the t-distribution is used.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 6 - 1 = 5

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 5 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.9}{2} = 0.95[/tex]. So we have T = 2.0.150

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}}[/tex]

In which s is the standard deviation of the sample and n is the size of the sample. So

[tex]M = 2.0150\frac{11.7}{\sqrt{6}} = 9.62[/tex]

The range of the true mean at 90% confidence level is of 9.62 hours.

(c)If a seventh sample is tested, what is the prediction interval (90% confidence level) of its failure time.

This is the confidence interval, so:

The lower end of the interval is the sample mean subtracted by M. So it is 49 - 9.62 = 39.38 hours.

The upper end of the interval is the sample mean added to M. So it is 49 + 9.62 = 58.62 hours.

The prediction interval, at a 90% confidence level, of it's failure time is between 39.38 hours and 58.62 hours.

Answer:

The p-value of the test if 0.0131, which is less than the standard significance level of 0.05, meaning that these data indicates that the self-worth of heroin addicts is less than that of the general population.

Step-by-step explanation:

On a test designed to measure self-worth, the mean for the general population is 48.6.

At the null hypothesis, we test if the mean is of 48.6, that is:

[tex]H_0: \mu = 48.6[/tex]

A psychologist suspects that heroin addicts have a different assessment of self-worth than others in the general population. Test if it is lower.

At the alternative hypothesis, we test if the mean is lower, that is:

[tex]H_1: \mu < 48.6[/tex]

The test statistic is:

We have the standard deviation for the sample, which means that the t-distribution is used to solve this question.

[tex]t = \frac{X - \mu}{\frac{s}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, s is the standard deviation and n is the size of the sample.

48.6 is tested at the null hypothesis:

This means that [tex]\mu = 48.6[/tex]

The psychologist obtains a random sample of 40 test scores produced by heroin addicts and found the sample mean and the sample standard deviations are 45.5 and 8.5, respectively.

This means that [tex]n = 40, X = 45.5, s = 8.5[/tex]

Value of the test statistic:

[tex]t = \frac{X - \mu}{\frac{s}{\sqrt{n}}}[/tex]

[tex]t = \frac{45.5 - 48.6}{\frac{8.5}{\sqrt{40}}}[/tex]

[tex]t = -2.31[/tex]

P-value of the test:

The p-value of the test is a one-tailed test(mean lower than a value), with t = -2.31 and 40 - 1 = 39 df.

Using a t-distribution calculator, this p-value is of 0.0131.

The p-value of the test if 0.0131, which is less than the standard significance level of 0.05, meaning that these data indicates that the self-worth of heroin addicts is less than that of the general population.

Answer:

Step-by-step explanation:

the answer is 2250 percent is = 22.5

Answer:

18% discount

Step-by-step explanation:

Percent discount is found by the following formula:

[tex]\frac{original-discount}{original}[/tex]

In this scenario, the original is 12500 and the discount, or special is 10250.

We can plug this into the formula to get

[tex]\frac{12500-10250}{12500}[/tex]

We can simplify the numerator by subtracting, and we get that answer as 2250.

We get the remainder of the answer as 2250 divided by 12500. We divide that, and get the answer as 0.18, which can be rewritten as 18%.

Answer:

gkg8fyaueajrkvxogogzoggkdggkdyyskyyeykektkykyksskysysskkyky

Answer:

The absolute maximum is about -5.84 at x = -2.

And the absolute minimum is about -11.28 at x = -π/6.

Step-by-step explanation:

We want to find the absolute maximum and minimum values of the function:

[tex]\displaystyle f(x) = 5x-10\cos x\text{ for } -2\leq x\leq 0[/tex]

First, we should evaluate the endpoints of the interval:

[tex]\displaystyle f(-2) = 5(-2) - 10\cos (-2) \approx -5.8385[/tex]

And:

[tex]f(0) = 5(0) -10\cos (0) = -10[/tex]

Recall that extrema of a function occurs at its critical points. The critical points of a function are whenever its derivative is zero or undefined.

So, find the derivative of the function:

[tex]\displaystyle f'(x) = \frac{d}{dx}\left[ 5x - 10\cos x\right][/tex]

Differentiate:

[tex]\displaystyle f'(x) = 5 + 10\sin x[/tex]

Set the function equal to zero:

[tex]\displaystyle 0 = 5+10\sin x[/tex]

And solve for x:

[tex]\displaystyle \sin x = -\frac{1}{2}[/tex]

Using the unit circle, our solutions are:

[tex]\displaystyle x = \frac{7\pi}{6} + 2n\pi\text{ or } \frac{11\pi}{6} + 2n\pi \text{ where } n\in \mathbb{Z}[/tex]

There is only one solution in the interval [-2, 0]:

[tex]\displaystyle x = \frac{11\pi}{6} - 2\pi = -\frac{\pi}{6}\approx -0.5236[/tex]

Thus, we only have one critical point on the interval.

Substituting this back into the function yields:

[tex]\displaystyle\begin{aligned} f\left(-\frac{\pi}{6}\right) &= 5\left(-\frac{\pi}{6}\right) - 10\cos \left(-\frac{\pi}{6}\right) \\ \\ &=-\frac{5\pi}{6} - 5\sqrt{3}\\ \\ &\approx -11.2782 \end{aligned}[/tex]

In conclusion, the absolute maximum value of f on the interval [-2, 0] is about -5.8385 at x = -2 and the absolute minimum value of f is about -11.2782 at x = -π/6.

We can see this from the graph below as well.

Answer:

38 divided by 10 equals 3.8

9514 1404 393

Answer:

  21

Step-by-step explanation:

The number who bought expensive tickets is 3/5 of the number who bought cheap tickets.

  (3/5)(35) = 21

21 people bought the more expensive ticket.

Answer:

21 people

Step-by-step explanation:

       $9.75      $14.50

  5 people to 3 people

 35 people to ? people

consider the proportions: 5/3 = 35/?

we need the equivalent fraction of 5/3 that has 35 on the denominator

so 5/3 = (5/3)(7/7)  because 7/7 =1, and 5*3 =35

5/3 = 5*7/3*7 = 35/21

Answer:

28

Step-by-step explanation:

10/14 mph no wind

20 wind

14 x 2 = 28

28 mph with wind

Answer:

this is the answer

681,474

Answer:

The coefficient of the squared term is 1/25.

Step-by-step explanation:

We are given that the vertex of a parabola is at (2, -4). We also know that y = -3 when x = -3.

And we want to determine the coefficient of the squared term of the equation.

Since we are given the vertex, we can use the vertex form of the quadratic:

[tex]\displaystyle y = a(x-h)^2+k[/tex]

Where (h, k) is the vertex and a is the leading coefficient. The leading coefficient is also the coefficient of the squared term, so we simply need to find the value of a.

Since the vertex is at (2, -4), h = 2 and k = -4. Substitute:

[tex]\displaystyle y = a(x-2)^2-4[/tex]

y = -3 when x = -3. Solve for a:

[tex]\displaystyle (-3) = a((-3)-2)^2-4[/tex]

Simplify:

[tex]\displaystyle 1 = a(-5)^2\Rightarrow a = \frac{1}{25}[/tex]

Therefore, our function in vertex form is:

[tex]\displaystyle f(x) = \frac{1}{25}\left(x-2)^2-4[/tex]

Hence, the coefficient of the squared term is 1/25.

Answer:

-5

Step-by-step explanation:

from a p e x

Answer:

7x - 6 = -2x + 2

Step-by-step explanation:

Hi! First we are going to distribute our "2" and "-2" values to the values in parenthesis.

5x + 2x - 6 = -2x + 2

Now, we can combine our like terms, "5x" and "2x".

7x - 6 = -2x + 2

Since our problem's answers are left in this form, not completely combined our answer is 7x - 6 = -2x + 2.

Hope this Helps! :)

Have any questions? Ask below in the comments and I will try my best to answer.

-SGO

Answer:

25

Step-by-step explanation:

5:20  

We want to get the second number to 100

100/20 = 5

Multiply each term by 5

5*5 : 20*5

25 : 100

x is 25

Given that,

→ 5 : 20 :: x : 100

Then we have to,

find the second number to 100.

→ 100/20

→ 5

Now multiply each term by 5 in 5:20,

→ 5 × 5 : 20 × 5

→ 25 : 100

→ x = 25

Now these ratio will be,

→ 5 : 20 :: 25 : 100

Hence, the value of x is 25.