# [help] how to prove this equation

1. Aug 14, 2006

### goodness52200

http://xs305.xs.to/xs305/06332/ss.gif [Broken]

Hello all, how to prove the above equation
thanks a lot

Last edited by a moderator: May 2, 2017
2. Aug 15, 2006

### VietDao29

Could you explain what $$s, \sigma , \ j, \ \omega$$ are? Are they constants, negative or positive?

3. Aug 15, 2006

### goodness52200

hi ViettDao29
s is a complex

4. Aug 15, 2006

### yenchin

Oh... so j is our usual i=sqrt(-1) :tongue:
Use an inequality for integral that absolute value of integral is less than or equal to integral of absolute value. Then consider that

$$|e^{-s}| = |e^{- \sigma}| |e^{-j \omega}|$$

Now, what is $|e^{-j \omega}|$ ?

Last edited: Aug 15, 2006
5. Aug 15, 2006

### benorin

Also recall that $$\, \left| \int f(x) \, dx\right| \leq \int\left| f(x) \right| \, dx$$