Finding g(t) with Laplace Transform of G(S)

In summary, the problem involves finding g(t) given the expressions G(S) = 2/s(e^-3s_e^-4s) and G(S) = (2S+1/S^2)*e^-2s_(3s+1/s^2)*e-3s. The specific operations involved are unclear without parentheses and clarification on the use of '_' in exponents.
  • #1
goodtime
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G(S)=2/s(e^-3s_e^-4s)

G(S)=(2S+1/S^2)*e^-2s_(3s+1/s^2)*e-3s


find g(t)?
 
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  • #2
goodtime said:
G(S)=2/s(e^-3s_e^-4s)

G(S)=(2S+1/S^2)*e^-2s_(3s+1/s^2)*e-3s


find g(t)?
First off, what work have you already done?
Second, what operation does '_' represent in e^-3s_e^-4s? If it's multiplication, you can write it as (e^(-3s)*e^(-4s))
Third, without parentheses, it's difficult to tell what's in the numerator of a rational expression, and what's in the denominator. E.g., does (2S + 1/S^2) in your second problem mean
[tex]2S + \frac{1}{S^2}[/tex]
or
[tex]\frac{2S + 1}{S^2}[/tex]?
 

FAQ: Finding g(t) with Laplace Transform of G(S)

How do I find g(t) using the Laplace Transform of G(s)?

The Laplace Transform of a function G(s) is defined as L{G(s)}=∫0g(t)e-stdt. To find g(t), we can use the inverse Laplace Transform, which is given by g(t)=1/2πi∫σ-i∞σ+i∞G(s)estds, where σ is a real number larger than the real parts of all singularities of G(s).

Can I use the Laplace Transform to find g(t) for any function G(s)?

No, the Laplace Transform is only defined for functions that are piecewise continuous on the interval [0,∞) and have exponential order, meaning that they grow no faster than an exponential function as t→∞. If a function does not meet these criteria, the Laplace Transform may not exist or may be difficult to compute.

Is it necessary to know the Laplace Transform of G(s) before finding g(t)?

Yes, to use the inverse Laplace Transform, we need to know the Laplace Transform of G(s). This can be found using tables or by solving the integral definition of the Laplace Transform. Alternatively, if we know the differential equation that relates g(t) and G(s), we can use the Laplace Transform to solve for G(s) and then find g(t) from the inverse Laplace Transform.

Can I use the Laplace Transform to find g(t) for a system with multiple inputs and outputs?

Yes, the Laplace Transform can be used for systems with multiple inputs and outputs. In this case, we would have multiple functions G1(s), G2(s), ..., Gn(s) representing the transforms of the different inputs, and we would use the inverse Laplace Transform to find g1(t), g2(t), ..., gn(t) for each input.

Are there any limitations to using the Laplace Transform to find g(t)?

One limitation of using the Laplace Transform is that it assumes the system is linear and time-invariant. This means that the input-output relationship of the system does not change over time and is not affected by the amplitude of the input. Additionally, the Laplace Transform is not well-suited for capturing transient behavior, or behavior that changes rapidly in a short period of time. In these cases, other methods may be more appropriate for finding g(t).

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