Recall that variation of parameters is used to solve second-order ODEs of the form
y''(t) + p(t) y'(t) + q(t) y(t) = f(t)
so the first thing you need to do is divide both sides of your equation by t :
y'' + (2t - 1)/t y' - 2/t y = 7t
You're looking for a solution of the form
[tex]y=y_1u_1+y_2u_2[/tex]
where
[tex]u_1(t)=\displaystyle-\int\frac{y_2(t)f(t)}{W(y_1,y_2)}\,\mathrm dt[/tex]
[tex]u_2(t)=\displaystyle\int\frac{y_1(t)f(t)}{W(y_1,y_2)}\,\mathrm dt[/tex]
and W denotes the Wronskian determinant.
Compute the Wronskian:
[tex]W(y_1,y_2) = W\left(2t-1,e^{-2t}\right) = \begin{vmatrix}2t-1&e^{-2t}\\2&-2e^{-2t}\end{vmatrix} = -4te^{-2t}[/tex]
Then
[tex]u_1=\displaystyle-\int\frac{7te^{-2t}}{-4te^{-2t}}\,\mathrm dt=\frac74\int\mathrm dt = \frac74t[/tex]
[tex]u_2=\displaystyle\int\frac{7t(2t-1)}{-4te^{-2t}}\,\mathrm dt=-\frac74\int(2t-1)e^{2t}\,\mathrm dt=-\frac74(t-1)e^{2t}[/tex]
The general solution to the ODE is
[tex]y = C_1(2t-1) + C_2e^{-2t} + \dfrac74t(2t-1) - \dfrac74(t-1)e^{2t}e^{-2t}[/tex]
which simplifies somewhat to
[tex]\boxed{y = C_1(2t-1) + C_2e^{-2t} + \dfrac74(2t^2-2t+1)}[/tex]
Parallel lines
What is the segment
Answer:
Step-by-step explanation:
help me with these questions
Answer:
24
Step-by-step explanation:
:) im in 8th do i already know this stuff
Find the area of the shaded region. Round to the nearest tenth. 11.1m 130°
Area = [ ? ] m²
The area of the shaded region is 294.5 m².
What is the area of the entire circle?The area of the entire circle is calculated as follows;
A = πr²
where;
r is the radius of the circleA = π ( 11.1² )
A = 387.1 m²
The area of the sector is calculated as follows;
A = ( θ/360 ) πr²
A = ( 130/360 ) x π ( 11.1² )
A = 139.8 m²
The area of the triangle is calculated as follows;
A = ¹/₂ ( sinθ )r²
A = ¹/₂ ( sin 130 ) (11.1²)
A = 47.2 m²
Area of the unshaded region is calculated as;
A' = 139.8 m² - 47.2 m²
A' = 92.6 m²
The area of the shaded region is calculated as follow;
A'' = 387.1 m² - 92.6 m²
A'' = 294.5 m²
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I WILL MARK THE ANSWER AS BRAINLIEST IF RIGHT
PLEASE HELP ME BE CORRECT BEFORE ANSWERING PLEASE
9514 1404 393
Answer:
D neither
Step-by-step explanation:
Reflection across a vertical line is required to change the figure left-to-right without changing it top-to-bottom. Translation along a directed line segment must then map corresponding points.
Sequence A involves reflection over a horizontal line, so can be rejected immediately. Sequence B does the translation so that point N gets moved to the location of point B. However, point N corresponds to point D (see the similarity statement), so that translation is inappropriate.
Neither sequence will map KLMN to ABCD.
Suppose the sales tax rate in Idaho is 6%. If a computer sells for $589, how much is
the sales tax?
Need helppppppp please
Answer:
What do you need help with
Step-by-step explanation:
Write an equation
that represents the line.
Answer:
the eq of given line is 2x+y+3=0
Please explain absolute values?
Answer:
the magnitude of a real number without regard to its sign.
Step-by-step explanation:
For example, |-3| would just be a 3 in general, no negative sign in the front.
hope this answers your confusion.
Choose the best graph that represents the linear equation:
y + 3 = 0
Graph A
On a coordinate plane, a line goes through (0, 3) and (1, 3).
Graph B
On a coordinate plane, a line goes through (negative 3, 0) and (negative 3, 1).
Graph C
On a coordinate plane, a line goes through (0, negative 3) and (1, negative 3).
Graph D
On a coordinate plane, a line goes through (0, 0) and (1, negative 3).
a.
Graph A
c.
Graph C
b.
Graph B
d.
Graph D
PLEASE HELP!!! Please select the best answer from the choices provided
A
B
C
D
Graph B is the best graph that represents the linear equation
Answer:
m=2b=1y=2x+1
just enter it
Identify the domain of the function shown in the graph.
A. -2 ≤ x ≤ 2
B. {-2,2}
C. x is all real numbers.
D. x > -2
Answer:
C. x is all real numbers
Step-by-step explanation:
Think of domain as how far the graph expands on the x-axis as asymptotes as the limits. So in this case, the graph extends infinitely on the x-axis; so it should be all real numbers.
True or False: The points T, Z, W and U coplanar in the following image
Answer:
False
Step-by-step explanation:
Points T & W are coplanar. Point Z is on both planes, so it depends on how you see it. HOWEVER, Point U is on another plane (plane Q to be exact), so points T, Z, W, and U are NOT coplanar.
Hope it helps (●'◡'●)
If a translation of T.3. - 8(x, y) is applied to square
ABCD, what is the y-coordinate of B'?
4
3
0-12
A
В
-8
-E
5
2
3
4
0
D
C
Answer:
Its C. -6
Step-by-step explanation:
The coordinates of point B after translation are (-2, -6).
What is Graph?Graph is a mathematical representation of a network and it describes the relationship between lines and points.
A translation T(-3, -8) follows the rule:
A translation is a movement of the graph either horizontally parallel to the -axis or vertically parallel to the -axis.
(x, y)--->(x-3, y-8)
From the diagram you can see that point B has coordinates (1,2).
(1, 2)--->(1-3, 2-8)
(1, 2)--->(-2, -6)
According to the previous rule this point will transform in point B' with coordinates (-2,-6),
Hence, the coordinates of point B after translation are (-2, -6).
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Omgg please help right now
Answer:
64in^3
Step-by-step explanation:
6×3 = 18
18×2 = 36
4×7 = 28
36+28 = 64
Hope this helps! :)
a. Consider the situation where you have three game chips, each labeled with one of the the numbers 3, 5, and 10 in a hat a. If you draw out 2 chips without replacement between each chip draw, list the entire sample space of po ssible results that can occur in the draw Use the three events are defined as follows, to answer parts b through n below:
Event A: the sum of the 2 drawn numbers is even.
Event B: the sum of the 2 drawn numbers is odd.
Event C: the sum of the 2 drawn numbers is a prime number
Now, using your answer to part a find the following probability values
b. P (A)=
c. P (B)=
d. P (C)=
e. P (A and C)-=
f. P(A or B)=
g. P (B andC)=
h. P(A or C)- =
i. P (C given B)=
j. P(C given A)=
k. P (not B)=
l. P (not C)=
Are events A and B mutually exclusive?Why or why not?
Are events B and C mutually exclusive? Why or why not?
Answer:
a) {3,5}{3,10}{5,10}
b) [tex]P(A)=\frac{1}{3}[/tex]
c) [tex]P(B)=\frac{2}{3}[/tex]
d) [tex]P(C)=\frac{1}{3}[/tex]
e) [tex]P(A and C)=0[/tex]
f) [tex]P(A or B)=1[/tex]
g) [tex]P(B and C)=\frac{1}{3}[/tex]
h) [tex]P(A or C)=\frac{2}{3}[/tex]
i) [tex]P(C given B)=\frac{1}{2}[/tex]
j) [tex]P(C given A)=0[/tex]
k) [tex]P(not B)=\frac{1}{3}[/tex]
l) [tex]P(not C)=\frac{2}{3}[/tex]
Yes, events A and B are mutually exclusive. Because the results can either be even or odd, not both. No, events B and C are not mutually exclusive because the result can be both, odd and prime.
Step-by-step explanation:
a)
In order to solve part a of the problem, we need to find the possible outcomes, in this case, the possible outcomes are:
{3,5}{3,10} and {5,10}
We could think of the oppsite order, for example {5,3}{10,3}{10,5} but these are basically the same as the previous outcomes, so we will just take three outcomes in our sample space. We can think of it as drawing the two chips at the same time.
b)
Now the probability of the sum of the chips to be even. There is only one outcome where the sum of the chips is even, {3,5} since 3+5=8 the other outcomes will give us an odd number, so:
[tex]P=\frac{#desired}{#possible}[/tex]
[tex]P(A)=\frac{1}{3}[/tex]
c) For the probability of the sum of the chips to be odd, there are two outcomes where the sum of the chips is odd, {3,10} since 3+10=13 and {5,10} since 5+10=15 the other outcomes will give us an even number, so:
[tex]P(B)=\frac{2}{3}[/tex]
d) The probability of the sum of the chips is prime. There is only one outcome where the sum of the chips is prime, {3,10} since 3+10=13 the other outcomes will give us non prime results, so:
[tex]P(C)=\frac{1}{3}[/tex]
e) The probability of the sum of the chips to be even and prime. There are no results where we can get an even and prime number, since the only even and prime number there is is number 2 and no outcome will give us that number, so:
P(A and C)=0
f) The probability of the sum of the chips is even or odd. We can either get even or odd results, so no matter what outcome we get, we will get an odd or even result so:
[tex]P(A or B)=1[/tex]
g) The probability of the sum of the chips is odd and prime. There is only one outcome where the sum of the chips is odd and prime, {3,10} since 3+10=13 the other outcomes will give us non prime results, so:
[tex]P(B and C)=\frac{1}{3}[/tex]
h) The probability of the sum of the chips is even or prime. There are two outcomes where the sum of the chips is even or prime, {3,10} since 3+10=13 and {3,5} since 3+5=8 so:
[tex]P(A or C)=\frac{2}{3}[/tex]
i) The probability of the sum of the chips is prime given that the sum of the chips is odd. There are two possible results where the sum of the chips is odd {3,10} and {5,10} and only one of those results is even, {3,10}, so
[tex]P(C given B)=\frac{1}{2}[/tex]
j) The probability of the sum of the chips is prime given that the sum of the chips is even. There is only one possible even result: {3,5} but that result isn't prime, so
[tex]P(C given A)=0[/tex]
k) The probability of the sum of the chips is not odd. There is only one outcome where the sum of the chips is not odd (even), {3,5} so:
[tex]P(not B)=\frac{1}{3}[/tex]
l) The probability of the sum of the chips is not prime. There are two outcomes where the sum of the chips is not prime, {3,5} and {5,10} so:
[tex]P(not C)=\frac{2}{3}[/tex]
Are events A and B mutually exclusive?
Yes, events A and B are mutually exclusive.
Why or why not?
Because the results can either be even or odd, not both.
Are events B and C mutually exclusive?
No, events B and C are not mutually exclusive.
Why or Why not?
Because the result can be both, odd and prime.
xp-q+1×xq-r+1×xr-p+1
Answer:
Look into the picture
Step-by-step explanation:
Let me know if there's something wrong to my answer
The number of diners at a restaurant each day is recorded and a daily average is calculated every month (assume 30 days in a month). The number of diners each day has a mean of 107 and a standard deviation of 60, but does not necessarily follow a normal distribution.The probability that a daily average over a given month is greater than x is 2.5%. Calculate x. You may find standard normal table useful. Give your answer to 3 decimal places.x =
Answer:
x = 128.472
Step-by-step explanation:
To solve this question, we need to understand the normal probability distribution and the central limit theorem.
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.
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.
The number of diners each day has a mean of 107 and a standard deviation of 60.
This means that [tex]\mu = 107, \sigma = 60[/tex]
Distribution of the daily average:
Over a month of 30 days, so [tex]n = 30, s = \frac{60}{\sqrt{30}} = 10.955[/tex]
The probability that a daily average over a given month is greater than x is 2.5%. Calculate x.
This is X when Z has a p-value of 1 - 0.025 = 0.975, so X when Z = 1.96. Then
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
By the Central Limit Theorem
[tex]Z = \frac{X - \mu}{s}[/tex]
[tex]1.96 = \frac{X - 107}{10.955}[/tex]
[tex]X - 107 = 1.96*10.955[/tex]
[tex]X = 128.472[/tex]
So x = 128.472
Cell Phone Service
Cellular phone service is available for $31 per month for 666 minutes. What is the
monthly cost per minute? Round your answer to the nearest tenth of a cent.
The cost for the phone service is
cents per minute.
9514 1404 393
Answer:
4.7¢/min
Step-by-step explanation:
To find the cost in cents per minute, divide the cost in cents by the number of minutes.
$31.00/(666 min) = (3100¢)/(666 min) ≈ 4.7¢/min
You paid $6.99 for a shirt that was 70% of what was the original price of the shirt?
Answer:
$23.3
Step-by-step explanation:
you can use ratios to solve this:
$6.99/x=0.30/0.100 then cross multiply to get 0.3x=6.99
So, 6.99 divided by 0.3 = 23.3
so the original price is $23.3
The maintenance department at the main campus of a large state university receives daily requests to replace fluorecent lightbulbs. The distribution of the number of daily requests is bell-shaped and has a mean of 54 and a standard deviation of 3. Using the 68-95-99.7 rule, what is the approximate percentage of lightbulb replacement requests numbering between 54 and 63?
Answer:
The approximate percentage of lightbulb replacement requests numbering between 54 and 63 is of 49.85%.
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
Approximately 68% of the measures are within 1 standard deviation of the mean.
Approximately 95% of the measures are within 2 standard deviations of the mean.
Approximately 99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 54, standard deviation = 3.
What is the approximate percentage of lightbulb replacement requests numbering between 54 and 63?
63 = 54 + 3*3
So between the mean and 3 standard deviations above the mean.
The normal distribution is symmetric, which means that 50% of the values are below the mean and 50% are above.
Of those 50% above, 99.7% are below 63. So
0.5*0.997 = 0.4985
0.4985*100% = 49.85%
The approximate percentage of lightbulb replacement requests numbering between 54 and 63 is of 49.85%.
Un automóvil consume 4 galones de gasolina al recorrer 180 kilómetros y para recorrer 900 kilómetros necesita 20 galones ¿cuántos kilómetros recorre por galón? ¿Cuantos galones consumirá en 2700 kilómetros?
Answer:
45 km por galón
60 galones en 2700 Km
Step-by-step explanation:
180 / 4
45 km por galón
900 / 45
20 galones
2700 / 45
60 galones en 2700 Km
Please help me there’s a image above.
Answer:
4,-1 that is the answer so
A bag has 180 balls. the ratio of red to blue to yellow balls is 8:5:7 how many red balls are there and how many blue balls are there
Answer:
72 red
45 blue
63 yellow
Step-by-step explanation:
8+5+7= 20
180÷20= 9
red = 9*8
blue = 9*5
yellow = 9*7
B
13 ft.
5 ft.
A
C
12 ft.
Find the value of Cos (B) =
Answer: the answer is 12/13
Question
The sum of three consecutive even integers is -312. Find the Integers.
Answer:
-105, -104, -103
Step-by-step explanation:
lets the numbers be:
x
x+1
x+2
so:
x+(x+1)+(x+2)=-312
x+x+x+1+2=-312
3x+3=-312
3x=-312-3=-315
x=-315/3=-105
What is the area of the trapezoid?
176 cm2
192 cm2
208 cm2
224 cm2
Answer:A. This is the formula for the area of a trapezoid: a+b/2 x height (a and b being the bases)
Step-by-step explanation: Use the formula. 10+12=22. 22/2 is 11. 11 x 16 is 176. Therefore, the answer is A.
team A ships 6 times as many as team B and one third as many as team C. if team C ships 287450 packages, how many packages does team B ships?
Answer:
95816.666667
explained
1÷3*287450
Identify the transformation that occurs to create the graph of g(x). g(x)=f(x)-7
Answer:
g(x) is obtained by shift the function f(x) down 7 units by subtracting 7 units from f(x).
Step-by-step explanation:
We are given that
[tex]g(x)=f(x)-7[/tex]
We have to identify the transformation that occurs to create the graph of g(x).
To identify the transformation that occurs to create the graph of g(x)
We will subtract the 7 from f(x).
Let f(x) be any function
[tex]g(x)=f(x)-k[/tex]
It means g(x) obtained by shift the function f(x) down k units by subtracting k units from f(x).
Therefore, g(x) is obtained by shift the function f(x) down 7 units by subtracting 7 units from f(x).
Which statement best compares the two functions? The minimum of function A occurs 1 unit higher than the minimum of function B. The minimum of function A occurs 3 units higher than the minimum of function B. The minimum of function A occurs 5 units lower than the minimum of function B. The minimum of function A occurs 7 units lower than the minimum of function B.
Answer: D: The minimum value of A occurs 7 units lower than minimum of function B.
Step-by-step explanation: The minimum of function A is at (3,-2), while the minimum of function B would be at (-3,5). So, you do 5-(-2) to get 7.
The minimum value of A occurs 7 units lower than the minimum of function B.
We have given that,
Statement best compares the two functions
What is the minimum and maximum function?
The maxima and minima of a function, known collectively as extrema, are the largest and smallest value of the function, either within a given range, or on the entire domain.
The minimum of function A is at (3,-2), while the minimum of function B would be at (-3,5). So, you do 5-(-2) to get 7.
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At any point in time, there could be bicycles, tricycles, and
cars in the school parking lot. Today, there are 53 wheels in
total.
If there are 15 bicycles, tricycles,
and cars in total, how many
tricycles could be in the parking lot? List all possible answers.
Answer:
There may be 1 or 3 tricycles in the parking lot.
Step-by-step explanation:
Since at any point in time, there could be bicycles, tricycles, and cars in the school parking lot, and today, there are 53 wheels in total, if there are 15 bicycles, tricycles, and cars in total, to determine how many tricycles could be in the parking lot, the following calculation must be performed:
13 x 4 + 1 x 3 + 1 x 2 = 57
11 x 4 + 1 x 3 + 3 x 2 = 53
10 x 4 + 3 x 3 + 2 x 2 = 53
8 x 4 + 5 x 3 + 2 x 2 = 51
10 x 2 + 1 x 3 + 4 x 4 = 39
9 x 3 + 1 x 2 + 5 x 4 = 49
Therefore, there may be 1 or 3 tricycles in the parking lot.
Suppose a tank contains 400 gallons of salt water. If pure water flows into the tank at the rate of 7 gallons per minute and the mixture flows out at the rate of 3 gallons per minute, how many pounds of salt will remain in the tank after 16 minutes if 28 pounds of salt are in the mixture initially? (Give your answer correct to at least three decimal places.)
Answer:
Step-by-step explanation:
This is a differential equation problem most easily solved with an exponential decay equation of the form
[tex]y=Ce^{kt}[/tex]. We know that the initial amount of salt in the tank is 28 pounds, so
C = 28. Now we just need to find k.
The concentration of salt changes as the pure water flows in and the salt water flows out. So the change in concentration, where y is the concentration of salt in the tank, is [tex]\frac{dy}{dt}[/tex]. Thus, the change in the concentration of salt is found in
[tex]\frac{dy}{dt}=[/tex] inflow of salt - outflow of salt
Pure water, what is flowing into the tank, has no salt in it at all; and since we don't know how much salt is leaving (our unknown, basically), the outflow at 3 gal/min is 3 times the amount of salt leaving out of the 400 gallons of salt water at time t:
[tex]3(\frac{y}{400})[/tex]
Therefore,
[tex]\frac{dy}{dt}=0-3(\frac{y}{400})[/tex] or just
[tex]\frac{dy}{dt}=-\frac{3y}{400}[/tex] and in terms of time,
[tex]-\frac{3t}{400}[/tex]
Thus, our equation is
[tex]y=28e^{-\frac{3t}{400}[/tex] and filling in 16 for the number of minutes in t:
y = 24.834 pounds of salt
