- #1

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i know that

L{f(t)} = [tex]\int[/tex]e

^{-st}f(t) dt = F(s)

so

L{f(t/b)} = [tex]\int[/tex]e

^{-st}f(t/b) dt

any tips on how to start? thx

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- Thread starter magnifik
- Start date

- #1

- 360

- 0

i know that

L{f(t)} = [tex]\int[/tex]e

so

L{f(t/b)} = [tex]\int[/tex]e

any tips on how to start? thx

- #2

Dick

Science Advisor

Homework Helper

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Do a u substitution to change the integration variable. Substitute u=t/b.

- #3

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do i also have to plug in (t/b) into e^{-st} so that it becomes e^{-s(t/b)} ?

- #4

Dick

Science Advisor

Homework Helper

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do i also have to plug in (t/b) into e^{-st}so that it becomes e^{-s(t/b)}?

You need to write e^(-st) in terms of u.

- #5

- 360

- 0

so..

u = t/b

t = bu

e^(-st)

e^(-sbu)

u = t/b

t = bu

e^(-st)

e^(-sbu)

- #6

Dick

Science Advisor

Homework Helper

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so..

u = t/b

t = bu

e^(-st)

e^(-sbu)

Sure. Now don't forget to add a factor to change the dt to a du.

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