i, I tried to solve this differential equation involving series methods, but I think the a2, a3, a4 factors might be wrong because I ended up with an "x" in the answer and there should just be number digits.  Could I get some help please? (x+1)y" + xy = 0 where initial conditions are y(0) = 1, y'(0) = 2.

Advanced Engineering Mathematics
10th Edition
ISBN:9780470458365
Author:Erwin Kreyszig
Publisher:Erwin Kreyszig
Chapter2: Second-order Linear Odes
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Hi, I tried to solve this differential equation involving series methods, but I think the a2, a3, a4 factors might be wrong because I ended up with an "x" in the answer and there should just be number digits.  Could I get some help please?

(x+1)y" + xy = 0

where initial conditions are y(0) = 1, y'(0) = 2.

Thank you.

### Solving Differential Equations Using Power Series Method

Consider the differential equation:

\[ (x+1)y'' + xy = 0 \]

with the initial conditions:

\[ y(0) = 1 \quad \text{and} \quad y'(0) = 2 \]

These initial conditions translate to the power series coefficients as:

\[ a_0 = 1 \]
\[ a_1 = 2 \]

Assume a solution of the form:

\[ y = \sum_{n=0}^{\infty} a_n x^n \]

### Deriving Representations for \( y' \) and \( y'' \)

Taking the derivatives, we get:

\[ y' = \sum_{n=1}^{\infty} n a_n x^{n-1} \Rightarrow y' = \sum_{n=0}^{\infty} (n+1) a_{n+1} x^n \]

\[ y'' = \sum_{n=2}^{\infty} n (n-1) a_n x^{n-2} \Rightarrow y'' = \sum_{n=0}^{\infty} (n+2)(n+1) a_{n+2} x^n \]

### Substituting into the Original Differential Equation
By substituting \( y \) and \( y'' \) into the original equation, we have:

\[ (x+1) \sum_{n=0}^{\infty} (n+2)(n+1) a_{n+2} x^n + x \sum_{n=0}^{\infty} a_n x^n = 0 \]

Combining terms and simplifying:

\[ \sum_{n=0}^{\infty} [(n+1)(n) a_{n+1} x^n + (n+2)(n+1) a_{n+2} x^n + x a_n] x^n = 0 \]

### Simplification Leads to Recurrence Relation
The above simplifies to:

\[ \sum_{n=0}^{\infty} \left[ (n+1)(n) a_{n+1} x^n + (n+2)(n+1) a_{n+2} x^n + x a_n \right] = 0 \]

Leading to the
Transcribed Image Text:### Solving Differential Equations Using Power Series Method Consider the differential equation: \[ (x+1)y'' + xy = 0 \] with the initial conditions: \[ y(0) = 1 \quad \text{and} \quad y'(0) = 2 \] These initial conditions translate to the power series coefficients as: \[ a_0 = 1 \] \[ a_1 = 2 \] Assume a solution of the form: \[ y = \sum_{n=0}^{\infty} a_n x^n \] ### Deriving Representations for \( y' \) and \( y'' \) Taking the derivatives, we get: \[ y' = \sum_{n=1}^{\infty} n a_n x^{n-1} \Rightarrow y' = \sum_{n=0}^{\infty} (n+1) a_{n+1} x^n \] \[ y'' = \sum_{n=2}^{\infty} n (n-1) a_n x^{n-2} \Rightarrow y'' = \sum_{n=0}^{\infty} (n+2)(n+1) a_{n+2} x^n \] ### Substituting into the Original Differential Equation By substituting \( y \) and \( y'' \) into the original equation, we have: \[ (x+1) \sum_{n=0}^{\infty} (n+2)(n+1) a_{n+2} x^n + x \sum_{n=0}^{\infty} a_n x^n = 0 \] Combining terms and simplifying: \[ \sum_{n=0}^{\infty} [(n+1)(n) a_{n+1} x^n + (n+2)(n+1) a_{n+2} x^n + x a_n] x^n = 0 \] ### Simplification Leads to Recurrence Relation The above simplifies to: \[ \sum_{n=0}^{\infty} \left[ (n+1)(n) a_{n+1} x^n + (n+2)(n+1) a_{n+2} x^n + x a_n \right] = 0 \] Leading to the
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