The problem is from Fourier Series in Undergraduate 400 level. - Please show each step of your solution. When you use theorems, definitions, etc., please include in your answer.
Fourier Cosine and Sine Transforms, and Passage from Fourier Integral to Laplace Tra ...
Laplace Transform - Use the definition of Laplace transform to find [t*e^kt].
Fourier Cosine Transform - The problem is from Fourier Cosine and Sine Transforms, and Passage from Fourier Integral to Laplace Transform:
Solve using a cosine or sine transform.
u'' - 9u =50e^-3x (0