Answer:
Step-by-step explanation:
but is their any answer choices
is it A. B. Or C.
please help
Answer:c?
Step-by-step explanation:
Answer:
B
Step-by-step explanation:
The radius of a circle is 4 feet. What is the area?
r=4ft
Give the exact answer in simplest form.
Answer:
100.571429.
Step-by-step explanation:
2*22/7*(4)^2
=44/7*16
=100.571429
Roger brought some sponges. The number of packages he bought was 14 less than the number of sponges per package. Roger bought 51 sponges in all. How many packages of sponges did roger buy?
Answer:
the number of sponges per package bought be 32.5
Step-by-step explanation:
Let us assume the number of sponges per package be x
So the number of packages he bought be x - 14
And, the overall he bought 51 sponges
So
the number of packages of sponges did roger buy is
x + x - 14 = 51
2x = 51 + 14
2x = 65
x = 32.5
So the number of sponges per package bought be 32.5
Can you help me for these 3 questions.
Answer:
Step-by-step explanation:
1) a + a
2) 2n+4 = 6n
3) 1
4n = 4
n = 1
Alberto invested $5,000 at 6% interest
compounded annually. What will be the
value of Alberto's investment after 8 years?
Answer:
$7969.24
Step-by-step explanation:
5000*1.06 to power of 8 = 7969.24037265
round to 2dp = $7969.24
Answer:
7400
Step-by-step explanation:
Ming le invited 12 people to her chrismas party.(that is,there are total 13 people at her party )Each person have each other person a present.How many presents were given
Answer:
There will be 13 gifts given in the party.
Step-by-step explanation:
Given that Ming invited 12 people to her chrismas party, with a total of 13 people at her party, and each person have each other person a present, to determine how many presents were given the following logical reasoning must be performed:
Given that there are 13 people at the party, and each of them will bring a gift, by mathematical logic there will be 13 gifts distributed in the party.
Answers this plz I need help
Answer:
y=2x+5
Step-by-step explanation:
u find the slope and since the y intercept is (0,5), that's the b value
hope this helps
Answer: 2x+5
Step-by-step explanation: calculate the slope of the points with the formula m= (y2-y1)/(x2-x1) then use the y-int to complete the equation
Find the area. 14 m 4.5 m 4.5 m 9m 12 m 3 m 3 m
plzzz help meeee
Answer:
52
Step-by-step explanation:
Which expression is equivalent to 1/4m + 3/4m- 3/8(m+1)?
Answer:
5/8m-3/8
Step-by-step explanation:
thats prolly it
A telephone company representative estimates that 40% of its customers have call-waiting service. To test this hypothesis, she selected a sample of 100 customers and found that 37% had call waiting. At α-0.01 , is there enough evidence to reject the claim?
Using the null-hypothesis to calculate the test-statistic at a significance level of 0.01, there is not enough evidence to reject the claim that 40% of the telephone company's customers have call-waiting service based on the sample data.
Is there enough evidence to reject the claim?To test the hypothesis that 40% of the telephone company's customers have call-waiting service, we can conduct a hypothesis test.
Let's set up the null and alternative hypotheses:
Null hypothesis (H₀): The proportion of customers with call-waiting service is 40%.
Alternative hypothesis (H₁): The proportion of customers with call-waiting service is not 40%.
We can use the t-test for proportions to perform the hypothesis test. The test statistic is given by:
z = (p - p₀) / √((p₀ * (1 - p₀)) / n)
where p is the sample proportion, p₀ is the hypothesized proportion, and n is the sample size.
In this case, p₀ = 0.40, p = 0.37, and n = 100.
Calculating the test statistic:
z = (0.37 - 0.40) / √((0.40 * (1 - 0.40)) / 100)
z = -0.03 / √(0.24 / 100)
z = -0.03 / 0.049
z = -0.612
To determine if there is enough evidence to reject the null hypothesis, we compare the calculated z-value with the critical z-value at a significance level of α = 0.01.
The critical z-value for a two-tailed test at α = 0.01 is approximately ±2.576.
Since -0.612 falls within the range of -2.576 to 2.576, we fail to reject the null hypothesis.
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Solve: |2x − 1| < 11.
Express the solution in set-builder notation.
{x|5 < x < 6}
{x|–5 < x < 6}
{x|x < 6}
{x|–6 < x < 6}
Answer:
the second one is the answer
Step-by-step explanation:
hope that helps
Answer:
B; {x|–5 < x < 6}
Step-by-step explanation:
The following data repite the resundew of students to short-zule test (out of 10) of cours Alb. X. and Cae). X 7 10 3 8 3 0 9 8 Sum 9 G 8 5 2 9 10 1. Calculate the correlation coeffici
The correlation coefficient between the scores of students in courses Alb. X and Cae is approximately -0.333.
Correlation refers to the strength of the relationship between two variables while coefficient refers to the numerical value that measures the strength of the correlation.
To calculate the correlation coefficient between the scores of students in courses Alb. X and Cae, we need to first organize the data into two separate lists or arrays representing the scores in each course. Let's denote the scores in Alb. X as X_scores and the scores in Cae as C_scores:
X_scores: 7, 10, 3, 8, 3, 0, 9, 8
C_scores: 8, 5, 2, 9, 10, 1
Next, we need to calculate the mean (average) of both sets of scores.
Mean of X_scores (denoted as X_mean):X_mean = (7 + 10 + 3 + 8 + 3 + 0 + 9 + 8) / 8
X_mean = 48 / 8
X_mean = 6
Mean of C_scores (denoted as C_mean):C_mean = (8 + 5 + 2 + 9 + 10 + 1) / 6
C_mean = 35 / 6
C_mean ≈ 5.83
Now, we calculate the covariance between the two sets of scores using the formula:cov(X_scores, C_scores) = Σ((X_i - X_mean) * (C_i - C_mean)) / (n - 1)
where Σ denotes the sum, X_i and C_i are individual scores, X_mean and C_mean are the means calculated above, and n is the number of scores.
Let's calculate the covariance:cov(X_scores, C_scores) = ((7-6)(8-5.83) + (10-6)(5-5.83) + (3-6)(2-5.83) + (8-6)(9-5.83) + (3-6)(10-5.83) + (0-6)(1-5.83) + (9-6)(8-5.83) + (8-6)(0-5.83)) / (8-1)
cov(X_scores, C_scores) ≈ -3.39
Next, we calculate the standard deviations of both sets of scores:
Standard deviation of X_scores (denoted as X_std):X_std = √(Σ(X_i - X_mean)² / (n - 1))
Let's calculate X_std:
X_std = √(((7-6)² + (10-6)² + (3-6)² + (8-6)² + (3-6)² + (0-6)² + (9-6)² + (8-6)²) / (8-1))
X_std ≈ 3.20
Standard deviation of C_scores (denoted as C_std):C_std = √(Σ(C_i - C_mean)² / (n - 1))
Let's calculate C_std:
C_std = √(((8-5.83)² + (5-5.83)² + (2-5.83)² + (9-5.83)² + (10-5.83)² + (1-5.83)²) / (6-1))
C_std ≈ 3.18
Finally, we can calculate the correlation coefficient (r) using the formula:r = cov(X_scores, C_scores) / (X_std * C_std)
Let's calculate r:
r ≈ -3.39 / (3.20 * 3.18)
r ≈ -3.39 / 10.176
r ≈ -0.333
Therefore, the correlation coefficient between the scores of students in courses Alb. X and Cae is approximately -0.333.
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Help, help, help! Quick Answer, please!
Answer:
3. 102
4. c
Step-by-step explanation:
For number 3:
(c^2 - a) + b becomes (10^2 - 3) + 5
10^2 = 100
100 - 3 + 5 = 102
For number 4:
Usually when you see distributive property, you're multiplying into parentheses. This time you're factoring out.
20c - 8d
It's not a, because that would be 20c + 8d
It's not b, because that would be 20c -32d
It is c, because 4 x 5c = 20 c and 4 x -2d = -8d
It's not d, because that would be 20c- 8cd
Let A(x)=∫x0f(t)dtA(x)=∫0xf(t)dt, with f(x)f(x) as in figure.
A(x)A(x) has a local minimum on (0,6)(0,6) at x=x=
A(x)A(x) has a local maximum on (0,6)(0,6) at x=x=
To determine the local minimum and local maximum of the function A(x) = ∫₀ˣ f(t) dt on the interval (0, 6), we need to analyze the behavior of A(x) and its derivative.
Let's denote F(x) as the antiderivative of f(x), which means that F'(x) = f(x).
To find the local minimum and maximum, we need to look for points where the derivative of A(x) changes sign. In other words, we need to find the values of x where A'(x) = 0 or A'(x) is undefined.
Using the Fundamental Theorem of Calculus, we have:
A(x) = ∫₀ˣ f(t) dt = F(x) - F(0)
Taking the derivative of A(x) with respect to x, we get:
A'(x) = (F(x) - F(0))'
Since F(0) is a constant, its derivative is zero, and we are left with:
A'(x) = F'(x) = f(x)
Now, let's analyze the behavior of f(x) based on the given figure to determine the local minimum and maximum of A(x) on the interval (0, 6). Without the specific information about the shape of the graph, it is not possible to determine the exact values of x that correspond to local minimum or maximum points.
To find the local minimum, we need to locate a point where f(x) changes from decreasing to increasing. This point would correspond to x = x_min.
To find the local maximum, we need to locate a point where f(x) changes from increasing to decreasing. This point would correspond to x = x_max.
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Use the method of variation of parameters to find a particular solution of the differential equation 4y" – 4y +y = 16et/2 that does ' not involve any terms from the homogeneous solution. = Y(t) =
The particular solution that does not involve any terms from the homogeneous solution is given by:[tex]Y(t) = C3 + C4te^(-t/2).[/tex]
To find a particular solution of the given differential equation using the method of variation of parameters, we follow these steps:
Solve the associated homogeneous equation: 4y" - 4y + y = 0.
The characteristic equation is:
[tex]4r^2 - 4r + 1 = 0.[/tex]
Solving the quadratic equation, we find two repeated roots: r = 1/2.
Therefore, the homogeneous solution is given by: y_h(t) = C1[tex]e^(t/2)[/tex] + C2t[tex]e^(t/2),[/tex] where C1 and C2 are constants.
Find the particular solution using the variation of parameters.
Let's assume the particular solution has the form:
[tex]y_p(t) = u1(t)e^(t/2) + u2(t)te^(t/2).[/tex]
To find u1(t) and u2(t), we differentiate this expression:
[tex]y_p'(t) = u1'(t)e^(t/2) + u1(t)(1/2)e^(t/2) + u2'(t)te^(t/2) + u2(t)e^(t/2) + u2(t)(1/2)te^(t/2).[/tex]
We equate the coefficients of e^(t/2) and te^(t/2) on both sides of the original equation:
[tex](1/2)(u1(t) + u2(t)t)e^(t/2) = 16e^(t/2).[/tex]
From this, we can deduce that u1(t) + u2(t)t = 32.
Differentiating again:
[tex]y_p''(t) = u1''(t)e^(t/2) + u1'(t)(1/2)e^(t/2) + u1'(t)(1/2)e^(t/2) + u1(t)(1/4)e^(t/2) + u2''(t)te^(t/2) + u2'(t)e^(t/2) + u2'(t)(1/2)te^(t/2) + u2(t)e^(t/2) + u2(t)(1/2)te^(t/2).[/tex]
Setting the coefficient of [tex]e^(t/2)[/tex]equal to zero:
[tex](u1''(t) + u1'(t) + (1/4)u1(t))e^(t/2) = 0.[/tex]
Similarly, setting the coefficient of [tex]te^(t/2)[/tex]equal to zero:
[tex](u2''(t) + u2'(t) + (1/2)u2(t))te^(t/2) = 0.[/tex]
These two equations give us a system of differential equations for u1(t) and u2(t):
u1''(t) + u1'(t) + (1/4)u1(t) = 0,
u2''(t) + u2'(t) + (1/2)u2(t) = 0.
Solving these equations, we obtain:
u1(t) = C3[tex]e^(-t/2)[/tex] + C4t[tex]e^(-t/2),[/tex]
u2(t) = -4C3[tex]e^(-t/2)[/tex] - 4C4t[tex]e^(-t/2).[/tex]
Substitute the values of u1(t) and u2(t) into the assumed particular solution:
[tex]y_p(t) = (C3e^(-t/2) + C4te^(-t/2))e^(t/2) - 4C3e^(-t/2) - 4C4te^(-t/2).[/tex]
Simplifying further:
[tex]y_p(t) = C3 + C4te^(-t/2) - 4C3e^(-t/2) - 4C4te^(-t/2).[/tex]
So, the particular solution that does not involve any terms from the homogeneous solution is given by:
[tex]Y(t) = C3 + C4te^(-t/2).[/tex]
Here, C3 and C4 are arbitrary constants that can be determined using initial conditions or boundary conditions if provided.
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Plz help! Due tonight!
During halftime of a football game, a slingshot launches T-shirts at the crowd. A T-shirt is launched from a height of 4 feet with an initial upward velocity of 80 feet per second. The T-shirt is caught 41 feet above the field. How long will it take the T-shirt to reach its maximum height? What is the maximum height? What is the range of the function that models the height of the T-shirt over time?
Question (5 points): Using Laplace transform to solve the IVP: y" + 5y = eat, y(0) = 0, y' (O) = 0, then, we have Select one: y(t) =(-1 1 93 – 4s2 + 5s – 20 O y(t) = 2-1 1 482 33 5s + 20 O None of these. Ο Ο 1 yt 3 – (t) = c{+60-60-20) {{+40 + 5a + 20 O 1 y(t) = 2-1
Given the differential equation is y''+5y = e^(at) with initial conditions y(0) = 0 and y'(0) = 0, the correct answer is: y(t) = (-1/5√(5)) cos (√(5)t)+(1/5) sin (√(5)t).
To solve the given initial value problem using Laplace transform, we need to apply Laplace transform on both sides of the differential equation.
y''+5y=e^(at) L{y''+5y} = L{e^(at)) s^2Y(s)-sy(0)-y'(0)+5Y(s)=1/(s-a) [by Laplace transform formula] s^2Y(s)+5Y(s)=1/(s-a) ... [i]
Applying Laplace transform on both sides, we get:
L{y''+5y}=L{e^(at))
Using the initial conditions, we get Y(s)=1/[(s-a)(s^2+5)] Y(s) = [A/(s-a)] + [(Bs+C)sin(t)+ (Ds+E)cos(t)]/√(5) (i)
To find the values of A, B, C, D, and E, we take the inverse Laplace transform of both sides of equation (i) using partial fraction expansion. Let's solve for A:
Y(s)=A/(s-a)+(Bs+C)sin(t)/√(5)+(Ds+E)cos(t)/√(5)
Multiplying by s-a on both sides: (s-a)Y(s)=A+Bssin(t)/√(5)+Csincos(t)/√(5)+Dscos(t)/√(5)+Esin(t)/√(5)
Taking the inverse Laplace transform: y(t)=Ae^(at)+(B/√(5))sin(√(5)t)+(C/√(5))cos(√(5)t)+(D/√(5))cos(√(5)t)+(E/√(5))sin(√(5)t)
Differentiating y(t) with respect to t, we get:
y'(t)=Aae^(at)+Bcos(√(5)t)-Csin(√(5)t)-Dsin(√(5)t)+Ecos(√(5)t)
Using the initial conditions, y(0)=0 and y'(0)=0 in equation (iii), we get:
0=A+E ...(iv)0=A+B/√(5)+D/√(5) ...(v)
Solving equations (iv) and (v) simultaneously, we get A=0, B=√(5)/5, D=-√(5)/5, and E=0
Substituting these values in equation (iii), we get: y(t)=(√(5)/5)sin(√(5)t)-(√(5)/5)cos(√(5)t)
Therefore, the correct answer is: y(t)= (-1/5√(5))cos(√(5)t)+(1/5)sin(√(5)t).
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6.18 heart transplant success. the stanford university heart transplant study was conducted to determine whether an experimental heart transplant program increased lifespan. each patient entering the program was officially designated a heart transplant candidate, meaning that he was gravely ill and might benefit from a new heart. patients were randomly assigned into treatment and control groups. patients in the treatment group received a transplant, and those in the control group did not. the table below displays how many patients survived and died in each group.22 control treatment alive 4 24 dead 30 45 suppose we are interested in estimating the difference in survival rate between the control and treatment groups using a confidence interval. explain why we cannot construct such an interval using the normal approximation. what might go wrong if we constructed the confidence interval despite this problem?
We cannot construct a confidence interval using the normal approximation in this case because the sample sizes of the control and treatment groups are relatively small (less than 30), and the data does not meet the assumptions required for the normal approximation.
The normal approximation assumes that the data follows a normal distribution, and for sample sizes less than 30, the distribution of the sample mean may not be well approximated by a normal distribution. In addition, the normal approximation assumes that the observations are independent, which may not hold true in this study due to the nature of the treatment and control groups.
If we constructed a confidence interval despite these problems, the interval may not accurately reflect the true difference in survival rates between the control and treatment groups. The interval could be biased or too wide/narrow, leading to incorrect conclusions about the effectiveness of the heart transplant program. Therefore, it is important to use appropriate statistical methods that account for the specific characteristics of the data and study design in order to obtain reliable estimates and valid inferences.
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Is 0.25 greater or less than 0.03?
Answer:
0.25 is greater than 0.03
Step-by-step explanation:
You can solve this simply by looking for the position of the decimal point.
For example, 0.30 is greater than 0.25, but 0.03 is less than 0.250.25 > 0.03
Answer:
Step-by-step explanation:
please help dont answer with random
Answer:
Step-by-step explanation:
17x + 14 + 4x -2 = 21x + 12
21x + 12 = 180
-12 -12
21x = 168
x = 8 degrees
[tex]\boxed{\large{\bold{\green{ANSWER~:) }}}}[/tex]
Here,
The two lines l and m are parallel,
cut by a transversat line t
So The two angles are supplementary each other.
we know that,The sum of two supplementary angles are 180°
According to the question,(17x+14)°+(4x-2)°=180°
17x+14°+4x-2°=180°
17x+4x+14°-2°=180°
21x+12°=180°
21x=180°-12°
21x=168°
x=168°/21
x=8°
Therefore,The value of x is 8°
Identify the type of conic that follwoing equation represents and write the standard form of each equation.
25x² + 100y² - 450x - 400y - 75 = 0
The standard form of the equation for the ellipse is ((x - 9)²/376) + ((y - 2)²/94) = 1.
The given equation represents an ellipse. The standard form of the equation is ((x-h)²/a²) + ((y-k)²/b²) = 1, where (h,k) is the center of the ellipse, 'a' is the semi-major axis, and 'b' is the semi-minor axis.
To determine the type of conic represented by the equation, we examine the coefficients of the x² and y² terms. In the given equation, both the x² and y² terms have positive coefficients, indicating that it represents an ellipse.
To write the equation in standard form, we need to complete the square for both the x and y terms. Let's rearrange the equation:
25x² - 450x + 100y² - 400y = 75
Now, we group the x and y terms and complete the square separately:
25(x² - 18x) + 100(y² - 4y) = 75
To complete the square for the x term, we take half of the coefficient of x (-18/2 = -9) and square it to get 81. Similarly, for the y term, we get 4.
25(x² - 18x + 81) + 100(y² - 4y + 4) = 75 + 25*81 + 100*4
Simplifying further:
25(x - 9)² + 100(y - 2)² = 9400
Dividing both sides by 9400, we get:
((x - 9)²/376) + ((y - 2)²/94) = 1
Therefore, the standard form of the equation for the ellipse is ((x - 9)²/376) + ((y - 2)²/94) = 1.
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The approximation of 1 = integral (x – 3)e** dx by composite Trapezoidal rule with n=4 is: -25.8387 4.7846 -5.1941 15.4505
The approximation of the integral I is -5.1941 using the composite Trapezoidal rule with n = 4.
We need to divide the interval [0, 2] into subintervals and apply the Trapezoidal rule to each subinterval.
The formula for the composite Trapezoidal rule is given by:
I = (h/2) × [f(x₀) + 2f(x₁) + 2f(x₂) + ... + 2f(xₙ₋₁) + f(xₙ)]
Where:
h = (b - a) / n is the subinterval width
f(xi) is the value of the function at each subinterval point
In this case, n = 4, a = 0, and b = 2. So, h = (2 - 0) / 4 = 0.5.
Now, let's calculate the approximation:
[tex]f\left(x_0\right)\:=\:f\left(0\right)\:=\:\left(0\:-\:3\right)e^{\left(0^2\right)}\:=\:-3[/tex]
[tex]f\left(x_1\right)\:=\:f\left(0.5\right)\:=\:\left(0.5\:-\:3\right)e^{\left(0.5^2\right)}\:=-2.535[/tex]
[tex]f\left(x_2\right)\:=\:f\left(1\right)\:=\:\left(1\:-\:3\right)e^{\left(1^2\right)}\:=\:-1.716[/tex]
[tex]f\left(x_3\right)\:=\:f\left(1.5\right)\:=\:\left(1.5\:-\:3\right)e^{\left(1.5^2\right)}\:=\:-1.051[/tex]
[tex]f\left(x_4\right)\:=\:f\left(2\right)\:=\:\left(2\:-\:3\right)e^{\left(2^2\right)}\:=\:-0.065[/tex]
Now we can plug these values into the composite Trapezoidal rule formula:
I = (0.5/2) × [-3 + 2(-2.535) + 2(-1.716) + 2(-1.051) + (-0.065)]
= (0.25)× [-3 - 5.07 - 3.432 - 2.102 - 0.065]
= -5.1941
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Angle W is shown in the diagram.
w
400
What is the measure of Angle w in degrees?
Answer:
The measure of Angle w in degrees is 50°
Step-by-step explanation:
We know that in a straight line, 180°
So,
90° + 40° + w = 180°
130° + w = 180°
w = 180° - 130°
w = 50°
Thus, The measure of Angle w in degrees is 50°
-TheUnknownScientist
Which describes the graph of the inequality g(x)>2√3x+2?
A. Shading above a solid line
B. Shading above a dotted line
C. Shading below a dotted line
D. Shading below a solid line
Answer:
A. Shading above a solid line.
Step-by-step explanation:
Let [tex]f(x) = 2\sqrt{3}\cdot x + 2[/tex], whose domain is all real numbers, since it is a first order polynomial (linear function) and meaning that for all element of [tex]x[/tex] exists one and only one value for [tex]f(x)[/tex], meaning a solid line. If [tex]g(x) > f(x)[/tex], then the range of all possible results is a shade area above the solid line.
Hence, the correct answer is A.
Which of the following is NOT true for 6s + 25 + 5? *
A. Represents an algebraic expression
B. There is only one value for s
C. A phrase that simplifies to two terms
D. There is a solution for s = 5
Answer:
B. There is only one value for s
Step-by-step explanation:
I hope this works for u.. :3
Can I have a brainliest plz :))
Answer? Please help!!
Answer:
true
Step-by-step explanation:
For a given norm on Rņwe call the matrix A ∈ Rmxn mxn isometry if ||AX|| = |x|| for all x ER". = • Show that the isometry must be regular. • Show that the set of isometries forms a
An isometry on R^n must be regular and the set of isometries forms a group under matrix multiplication.
An isometry is a linear transformation that preserves distances, meaning the norm of the transformed vector is equal to the norm of the original vector. To show that an isometry must be regular (i.e., invertible), we can assume there exists a non-invertible isometry matrix A. In this case, there exists a nonzero vector x such that Ax = 0. However, this contradicts the property of an isometry since ||Ax|| = ||0|| = 0, but ||x|| ≠ 0. Thus, an isometry must be regular.
The set of isometries forms a group under matrix multiplication because it satisfies the group axioms: closure (the product of two isometries is an isometry), associativity (matrix multiplication is associative), identity (identity matrix is an isometry), and inverses (the inverse of an isometry is also an isometry).
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−x+9y=
\,\,-19
−19
3x-3y=
3x−3y=
\,\,9
9
Answer:
9!
Step-by-step explanation:
Which statements are true based on the diagram?
Select three options.
By using the method of variation of parameters to solve a nonhomogeneous DE with W = -3 W2 = e 112 and W = er, we have ---- Select one: 42 Ou= 41 O U2= O None of these. -4 Ou2 = O U =
By using the method of variation of parameters to solve a nonhomogeneous DE with W = -3 W2 = e 112 and W = er, we have
Given: W1=-3, W2=e^t and W3=er.The general solution of the non-homogeneous differential equation, y" + p(t) y' + q(t) y = g(t) , where p(t) and q(t) are functions of t and g(t) is non-zero function is given by;{eq}y = y_c + y_p {/eq}Where {eq}y_c {/eq} is complementary function and {eq}y_p {/eq} is particular function obtained by using variation of parameters.The solution is as follows:The given differential equation is{eq}y''+3y'+2y=-3e^{-t}+e^{t}+re^t{/eq}Characteristic equation is{eq}m^2+3m+2=0{/eq}Solving above equation gives us, {eq}m=-1,-2{/eq}Therefore, complementary function {eq}y_c=c_1e^{-t}+c_2e^{-2t} {/eq}Now, we find the particular solution by using the method of variation of parameters.Let {eq}y_p=u_1e^{-t}+u_2e^{-2t}{/eq}be a particular solution where {eq}u_1{/eq} and {eq}u_2{/eq} are functions of {eq}t.{/eq}Here W is a Wronskian and is given as:{eq}W=\begin{vmatrix}W_1&W_2\\W_1'&W_2'\\\end{vmatrix}=\begin{vmatrix}-3&e^t\\-1&e^t\\\end{vmatrix}=2e^{2t}+3e^{t}{/eq}Now, we find {eq}u_1{/eq} and {eq}u_2{/eq} as follows:{eq}u_1=\frac{-\int W_2 g(t) dt}{W}=\frac{-\int e^t(-3e^{-t}+e^{t}+re^t)dt}{2e^{2t}+3e^{t}}=-\frac{r}{5}-\frac{7}{10}+\frac{3}{10}e^{t}{/eq}Similarly,{eq}u_2=\frac{\int W_1 g(t) dt}{W}=\frac{\int -3e^{-t}(-3e^{-t}+e^{t}+re^t)dt}{2e^{2t}+3e^{t}}=-\frac{r}{5}-\frac{1}{10}+\frac{3}{10}e^{-2t}{/eq}Hence, the general solution of the differential equation is {eq}y=y_c+y_p=c_1e^{-t}+c_2e^{-2t}-\frac{r}{5}-\frac{7}{10}+\frac{3}{10}e^{t}-\frac{r}{5}-\frac{1}{10}+\frac{3}{10}e^{-2t}{/eq}So, Option D, {eq}-4u_2=0,~u_1=-\frac{r}{5}-\frac{7}{10}+\frac{3}{10}e^{t},~u_2=-\frac{r}{5}-\frac{1}{10}+\frac{3}{10}e^{-2t}{/eq} is correct.
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