# Verify orthogonality integral by direct integration

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1. Mar 19, 2017

### physcisgirl

This is a heat equation related math problem.
1. The problem statement, all variables and given/known data

The complete question is: Verify the orthogonality integral by direct integration. It will be necessary to use the equation that defines the λ_n: κ*λ_n*cos(λ_n*a) + h*sin(λ_n*a)=0.

2. Relevant equations
κ*λ_n*cos(λ_n*a) + h*sin(λ_n*a)=0.

3. The attempt at a solution
I tried to integrate the above given equation, but it doesn't really make sense to me to integrate it. I'm not sure what orthogonality integral it wants me to integrate. I think it's related to fourier series sine and cosine, I also googled orthogonality integral, but couldn't find what I'm looking for. Any help for clarifying and how I should tackle this question would be greatly appriciated!

2. Mar 19, 2017

### BvU

Hello PG,

Seems to me you think we know what the context of your partial problem statement is, but we're pretty lousy at telepathy. Please provide some more context -- where does this exercise appear, what do the variables stand for, etc.