Question

y’’ -4y’ +4y = (12x^2 -6x)e^2x Y(0)= 1 Y’(0)=0 Y(x)=c1y1+c2y2+yp

76

likes
379 views

Answer to a math question y’’ -4y’ +4y = (12x^2 -6x)e^2x Y(0)= 1 Y’(0)=0 Y(x)=c1y1+c2y2+yp

Expert avatar
Corbin
4.6
107 Answers
To solve the given second-order linear homogeneous ordinary differential equation:
y'' - 4y' + 4y = (12x^2 - 6x)e^{2x}
We first find the complementary function (CF) by solving the associated homogeneous equation:
y'' - 4y' + 4y = 0
The auxiliary equation is obtained by substituting y = e^{rx} into the homogeneous equation:
r^2e^{rx} - 4re^{rx} + 4e^{rx} = 0
Factoring out e^{rx}:
e^{rx}(r^2 - 4r + 4) = 0
Simplifying the quadratic equation:
r^2 - 4r + 4 = (r-2)^2 = 0
This implies a repeated root at r = 2, so the complementary function (CF) is:
y_{CF} = (c_1 + c_2x)e^{2x}

To find the particular integral (PI), we use the method of undetermined coefficients. Let's assume the particular solution is of the form:
y_{PI} = Ax^2e^{2x} + Bxe^{2x}
Now, let's find the first and second derivatives of y_{PI}:
y'_{PI} = (2Ax^2e^{2x} + 2Axe^{2x}) + (Be^{2x} + 2Bxe^{2x})
y''_{PI} = (4Ax^2e^{2x} + 8Axe^{2x} + 2Ae^{2x}) + (2Be^{2x} + 4Be^{2x} + 2Bxe^{2x})
Substituting these derivatives into the original differential equation and simplifying, we get:
(4Ax^2 + 12Bx + 12A - 6B)e^{2x} = (12x^2 - 6x)e^{2x}

Comparing coefficients, we have:
4Ax^2 + 12Bx + 12A - 6B = 12x^2 - 6x
Equating the coefficients of like powers of x:
4A = 12 \quad \text{(coefficient of }x^2)
12B + 12A - 6B = -6 \quad \text{(coefficient of }x)

Solving the equations, we find:
A = 3
B = -1

Therefore, the particular solution (PI) is:
y_{PI} = 3x^2e^{2x} - xe^{2x}

The general solution (GS) is the sum of the complementary function (CF) and the particular integral (PI):
y_{GS} = y_{CF} + y_{PI} = (c_1 + c_2x)e^{2x} + 3x^2e^{2x} - xe^{2x}

Using the initial conditions, we can find the values of c_1 and c_2. Given: y(0) = 1 and y'(0) = 0.

Substituting x = 0 and y = 1 into the general solution (GS):
y_{GS}(0) = (c_1 + c_2 \cdot 0)e^{2 \cdot 0} + 3 \cdot 0^2 e^{2 \cdot 0} - 0 \cdot e^{2 \cdot 0} = c_1 = 1

Substituting x = 0 and y' = 0 into the general solution (GS):
y'_{GS}(0) = (c_2)e^{2 \cdot 0} + 0 - 1 \cdot e^{2 \cdot 0} = c_2 - 1 = 0

Solving for c_2, we get:
c_2 = 1

Therefore, the solution to the differential equation is:
y(x) = (1 + x)e^{2x} + 3x^2e^{2x} - xe^{2x}

Answer: y(x) = (1 + x + 3x^2 - x)e^{2x} = (1 + 2x + 3x^2)e^{2x}

Frequently asked questions (FAQs)
What is the equation of the circle with center (2, -3) and a radius of 5 units?
+
Find the limit as x approaches 0 of (sin(x)/x)^2 + ln(1+x)/x,
+
Question: Simplify the expression (3x + 2)/(x^2 - 1) as x approaches 2.
+
New questions in Mathematics
How to find the value of x and y which satisfy both equations x-2y=24 and 8x-y=117
Let f(x)=||x|−6|+|15−|x|| . Then f(6)+f(15) is equal to:
𝑦 = ( 𝑥2 − 3) (𝑥3 + 2 𝑥 + 1)
a ferry travels 1/6 of the distance between two ports in 3/7 hour. the ferry travels at a constant rate. at this rate, what fraction of the distance between the two ports can the ferry travel in one hour?
431414-1*(11111-1)-4*(5*3)
-11+29-18
Write 32/25 as a percent
solve the following trigo equation for 0°<= x <= 360°. sec x =-2
2.5 / 21.85
An electrical company manufactures batteries that have a duration that is distributed approximately normally, with a mean of 700 hours and a standard deviation of 40 hours. Find the probability that a randomly selected battery has an average life of less than 810 hours.
2x+4x=
Primes are numbers divisible only by 1 and themselves; There are infinitely many prime numbers and the first ones are 2, 3, 5, 7, 11, 13, 17, 19, 23, .... Consider a 12-sided die, with the faces numbered from 1 to 12. Out of 4 rolls, the probability that only the first three numbers are primes is:
Raúl, Gilberto and Arturo are playing golf; The probabilities of winning for each one are as follows: (Raúl wins) = 20% (Gilberto wins) = 0.05% (Arturo wins) = ¾%. Perform operations and order events from least to most probable.
A machine produces 255 bolts in 24 minutes. At the same rate, how many bolts would be produced in 40 minutes?
prove that for sets SS, AA, BB, and CC, where AA, BB, and CC are subsets of SS, the following equality holds: (A−B)−C=(A−C)−(B−C)
Write the inequality in the form of a<x<b. |x| < c^2
8. Measurement Jillian measured the distance around a small fish pond to be 27 yards. What would be a good estimate of the distance across the pond: 14 yards, 9 yards, or 7 yards? Explain how you decided.
4m - 3t + 7 = 16
6(k-7) -2=5
To apply a diagnostic test, in how many ways can 14 students be chosen out of 25? if the order does not matter