Thomas Algorithm for Tridiagonal System

Question

A professor gave us an assignment to solve a Tridiagonal system using Thomas Algorithm. Here is the exercise:

I am lost as to what to do with that $(0.2\pi)^2$ and do I just calculate the $\sin(0.2\pi)$ to assign it as the value for equation 1?

I'm used to solving exercises like this one with Thomas Algorithm:

Can someone guide me in the right direction as to how to solve this? Maybe it's very simple and I am overthinking the whole $(0.2\pi)^2$ thing.

Thanks in advance!

Answer 1

Yes, you are overthinking the whole $\pi^2/25$ thing. Just multiply each of the components of the vector on the right by that factor; you are solving $$ M \vec{u} = \left( \begin{array}{c} \frac{\pi^2}{25}\sin(\pi/5) \\ \frac{\pi^2}{25}\sin(2\pi/5) \\ \frac{\pi^2}{25}\sin(3\pi/5) \\ \frac{\pi^2}{25}\sin(4\pi/5) \end{array}\right) $$