# ODE solution

## Homework Statement

Consider the following second order ODE
$$y'' + 2y' - y = e^{-x}, \quad y(0) = y'(0) = 1.$$ Convert this to a system of first order equations and use the pc33assisys MATLAB file to compute the solution for y(2).

## The Attempt at a Solution

The system of first order equations is
$$u_1' = u_2 \\ u_2' = e^{-x}-2u_2+u_1$$ with $$u_1(0) = u_2(0) = 1.$$
The solution for y(2) is y(2) = 3.27 to 2 d.p. But my pc33assisys file doesn't give me this. All the relevant files are attached to run the program. Can someone help figure out what is wrong with my code.

Thanks.

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Related Calculus and Beyond Homework Help News on Phys.org
There's a matrix indexing error in pc33assi3sys.m in the Adams-Moulton integration loop. Whoever wrote it also forgot to initialize f(1,:) for the first multi-step.

I've attached a corrected version.

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Cheers mate