Evaluating a function using techniques for solving linear systems

I really just need help on where to start with this problem. I know about LU decomposition and Cholesky decomposition as means of efficiently solving a linear system, but I'm unsure how to approach this problem.

Answer 1

[Carl]

An important part of solving a linear system efficiently is to avoid explicitly calculating the inverse, if possible. In MATLAB, this is often done using the mldivide (\) operator. See the page here for a high-level description of the various methods/optimizations it uses.

So in a function, something like:

inv(T)*inv(A)*x

can be replaced with:

T\(A\x)

On a related note, the transpose of a matrix or array x is written as x' in MATLAB.