Laplace Inverse Problems: 1/(s^2-6s+10) and s/(s+1)^2 Solutions

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SUMMARY

The discussion focuses on solving Laplace inverse problems, specifically for the functions 1/(s^2-6s+10) and s/(s+1)^2. The first function can be rewritten as 1/((s-3)^2 + 1), allowing the use of the standard Laplace transform F(s) = 1/(s^2 + 1). For the second function, the correct setup for partial fraction decomposition is crucial; it should be expressed as s/((s + 1)^2) = A/(s + 1) + B/(s + 1)^2, rather than incorrectly combining terms. These insights clarify the methods needed to approach these Laplace inverse problems effectively.

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  • Knowledge of partial fraction decomposition techniques
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Homework Statement



I have two problems i can't figure out , laplace inverse of 1/(s^2-6s+10) and laplace inverse of s/(s+1)^2

Homework Equations



I use the table of laplace transforms in my book

The Attempt at a Solution



For the first one i did the quadratic formula to solve for s but i still couldn't figure out the answeer

And the second one i split up the denominator and was thinkin a=-1 and b=-1 but i didnt get the right answer...im really having a hard timewith this stuff i feel like I am making it harder than it really is please help
 
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bdh2991 said:

Homework Statement



I have two problems i can't figure out , laplace inverse of 1/(s^2-6s+10) and laplace inverse of s/(s+1)^2

Homework Equations



I use the table of laplace transforms in my book

The Attempt at a Solution



For the first one i did the quadratic formula to solve for s but i still couldn't figure out the answeer

And the second one i split up the denominator and was thinkin a=-1 and b=-1 but i didnt get the right answer...im really having a hard timewith this stuff i feel like I am making it harder than it really is please help

For the first, 1/(s^2-6s+10) = 1/( (s - 3)2 + 1). You can think of this as F(s - 3), where F(s) = 1/(s2 + 1). I think this is the direction you should take, but I haven't worked this one through.

For the second one, I don't think you set up your partial fraction decomposition correctly. If you wrote it as
$$\frac{s}{(s + 1)^2} = \frac{A}{s+1} + \frac{B}{s+1}$$

that is incorrect.
It should be

$$\frac{s}{(s + 1)^2} = \frac{A}{s+1} + \frac{B}{(s+1)^2}$$
 
ya i realized the first one you have to complete the square but for i haven't reworked the second one i'll try the partial fractions and see if it works out...thanks for the help!
 

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