# Laplace transforms

mathrocks
Ok, this is the question:

Assume that the Laplace transform of x(t) is given as X(s)=s / (2s^(2) + 1).
Determine the Laplace transform of the following function.

g(t)=x(2t-5)u(2t-5)

How do I use the transform they have given me to solve this...I guess my major problem lies using time shifting and frequency scaling

Or if you have g(t)=t^2 sin(3t)x(t)...do you ignore x(t) since you usually ignore u(t) when it's at the end of the function?

Homework Helper
If you know the laplace transform of f(t), you how does the laplace transform of f(at) look? Or that of f(t-b)u(t-b)?

You can answer these questions generally, or you could setup the integral for the laplace transform of g(t) and make a change of variable.

mathrocks
Galileo said:
If you know the laplace transform of f(t), you how does the laplace transform of f(at) look? Or that of f(t-b)u(t-b)?

You can answer these questions generally, or you could setup the integral for the laplace transform of g(t) and make a change of variable.

What happens to u(2t-5) though? Do you actually take the Laplace transform of that?

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