explain the problem---**Question Stem:**
Q: Solve the Sturm-Liouville eigenvalue problem:
**Differential Equation and Boundary Conditions:**
d²y/dx² + λy = 0, y(0) = 0, y(π) = 0
**Problem Explanation/Steps:**
Step 1: Identify the Type of Equation
The equation is a second-order linear homogeneous differential equation with boundary conditions, which forms a Sturm-Liouville problem.
The general Sturm-Liouville form is:
d/dx [p(x) dy/dx] + [λw(x) - q(x)] y = 0
For this problem:
* p(x) = 1
* q(x) = 0
* w(x) = 1
Step 2: General Solution of the ODE
Given:
$\frac{d^2y}{dx^2} + \lambda y = 0$
We solve the auxiliary (characteristic) equation:
$r^2 + \lambda = 0 \Rightarrow r = \pm i\sqrt{\lambda}$
So the general solution is:
$y(x) = A \cos(\sqrt{\lambda}x) + B \sin(\sqrt{\lambda}x)$
Step 3: Apply Boundary Conditions
First Condition:
$y(0) = 0 \Rightarrow A \cos(0) + B \sin(0) = A \cdot 1 + B \cdot 0 = 0 \Rightarrow A = 0$
So the simplified solution becomes:
```text
y(x) = B sin(sqrt(lambda) x)
Second Condition:
y(pi) = 0 => B sin(sqrt(lambda) * pi) = 0
Since B != 0 (non-trivial solution), we must have:
sin(sqrt(lambda) * pi) = 0 => sqrt(lambda) * pi = n pi => sqrt(lambda) = n
Thus,
lambda_n = n^2, n = 1, 2, 3, ...
Step 4: Write Final Answers
Eigenvalues:
[Checkbox checked] Eigenvalues:
lambda_n = n^2, n = 1, 2, 3, ...
[Checkbox checked] Eigenfunctions:
[Down arrow symbol]
```
Eigenfunctions:
$y_n(x) = \sin(nx)$, $n = 1, 2, 3, \dots$
Bonus (If you want to write more for full 10 marks):
Orthogonality of Eigenfunctions:
The eigenfunctions $\{\sin(nx)\}$ form an orthogonal set on the interval $[0, \pi]$ with respect to the weight function $w(x) = 1$:
$\int_{0}^{\pi} \sin(nx) \sin(mx)dx = \begin{cases} 0 & n \ne m \\ \frac{\pi}{2} & n = m \end{cases}$
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Let's solve a Sturm-Liouville eigenvalue problem. We have the differential equation d squared y over dx squared plus lambda y equals zero, with boundary conditions y of zero equals zero and y of pi equals zero. This is a second-order linear homogeneous differential equation that forms a classic Sturm-Liouville problem, commonly found in physics and engineering applications.