Solve the given differential equation by undetermined coefficients. y" - y'= -6 y(x) =

Calculus For The Life Sciences
2nd Edition
ISBN:9780321964038
Author:GREENWELL, Raymond N., RITCHEY, Nathan P., Lial, Margaret L.
Publisher:GREENWELL, Raymond N., RITCHEY, Nathan P., Lial, Margaret L.
Chapter11: Differential Equations
Section11.1: Solutions Of Elementary And Separable Differential Equations
Problem 17E: Find the general solution for each differential equation. Verify that each solution satisfies the...
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### Solving Differential Equations by Undetermined Coefficients

**Problem Statement:**

Solve the given differential equation by the method of undetermined coefficients.

\[ y'' - y' = -6 \]

**Solution Process:**

_y(x) = ______________

In this problem, you are tasked with solving the differential equation \( y'' - y' = -6 \) using the method of undetermined coefficients. The method of undetermined coefficients is a technique to find particular solutions to non-homogeneous linear differential equations with constant coefficients.

**Explanation of the Method:**

1. **Find the complementary solution** \( y_c(x) \):
   - Solve the associated homogeneous equation \( y'' - y' = 0 \).
   - The characteristic equation for this differential equation is obtained by replacing \( y'' \) with \( r^2 \) and \( y' \) with \( r \), resulting in \( r^2 - r = 0 \). Solving this quadratic equation gives the roots \( r = 0 \) and \( r = 1 \).
   - Therefore, the general solution to the homogeneous equation is:
     \[
     y_c(x) = C_1 e^{0x} + C_2 e^{1x} \implies y_c(x) = C_1 + C_2 e^x
     \]

2. **Find the particular solution** \( y_p(x) \):
   - For the non-homogeneous term \(-6\), guess a particular solution. Since the term is a constant, try \( y_p(x) = A \). Substitute \( y_p \) into the differential equation to determine \( A \).
   - Substituting \( y_p = A \) into \( y'' - y' = -6 \):
     \[
     0 - 0 = -6
     \]
     This suggests choosing \( y_p = A \) where \( A = -6 \).

3. **Combine the solutions**:
   - The general solution to the differential equation is the sum of the complementary and particular solutions:
     \[
     y(x) = y_c(x) + y_p(x) = C_1 + C_2 e^x - 6
     \]

Fill in the blank box with the final expression to assist with the problem-solving process.

**Answer:**
\[ y(x) = C_1
Transcribed Image Text:### Solving Differential Equations by Undetermined Coefficients **Problem Statement:** Solve the given differential equation by the method of undetermined coefficients. \[ y'' - y' = -6 \] **Solution Process:** _y(x) = ______________ In this problem, you are tasked with solving the differential equation \( y'' - y' = -6 \) using the method of undetermined coefficients. The method of undetermined coefficients is a technique to find particular solutions to non-homogeneous linear differential equations with constant coefficients. **Explanation of the Method:** 1. **Find the complementary solution** \( y_c(x) \): - Solve the associated homogeneous equation \( y'' - y' = 0 \). - The characteristic equation for this differential equation is obtained by replacing \( y'' \) with \( r^2 \) and \( y' \) with \( r \), resulting in \( r^2 - r = 0 \). Solving this quadratic equation gives the roots \( r = 0 \) and \( r = 1 \). - Therefore, the general solution to the homogeneous equation is: \[ y_c(x) = C_1 e^{0x} + C_2 e^{1x} \implies y_c(x) = C_1 + C_2 e^x \] 2. **Find the particular solution** \( y_p(x) \): - For the non-homogeneous term \(-6\), guess a particular solution. Since the term is a constant, try \( y_p(x) = A \). Substitute \( y_p \) into the differential equation to determine \( A \). - Substituting \( y_p = A \) into \( y'' - y' = -6 \): \[ 0 - 0 = -6 \] This suggests choosing \( y_p = A \) where \( A = -6 \). 3. **Combine the solutions**: - The general solution to the differential equation is the sum of the complementary and particular solutions: \[ y(x) = y_c(x) + y_p(x) = C_1 + C_2 e^x - 6 \] Fill in the blank box with the final expression to assist with the problem-solving process. **Answer:** \[ y(x) = C_1
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ISBN:
9780321964038
Author:
GREENWELL, Raymond N., RITCHEY, Nathan P., Lial, Margaret L.
Publisher:
Pearson Addison Wesley,