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Table of Laplace Transform Pairs

Laplace Transform Pairs
Transform Pair Signal Transform ROC
1 $ \,\!\delta(t) $ $ 1 $ $ All\,\, s $
2 $ \,\! u(t) $ $ \frac{1}{s} $ $ \mathcal{R} \mathfrak{e} \lbrace s \rbrace > 0 $
3 $ \,\! -u(-t) $ $ \frac{1}{s} $ $ \mathcal{R} \mathfrak{e} \lbrace s \rbrace < 0 $
4 $ \frac{t^{n-1}}{(n-1)!}u(t) $ $ \frac{1}{s^{n}} $ $ \mathcal{R} \mathfrak{e} \lbrace s \rbrace > 0 $
5 $ -\frac{t^{n-1}}{(n-1)!}u(-t) $ $ \frac{1}{s^{n}} $ $ \mathcal{R} \mathfrak{e} \lbrace s \rbrace < 0 $
6 $ \,\!e^{-\alpha t}u(t) $ $ \frac{1}{s+\alpha} $ $ \mathcal{R} \mathfrak{e} \lbrace s \rbrace > -\alpha $
7 $ \,\! -e^{-\alpha t}u(-t) $ $ \frac{1}{s+\alpha} $ $ \mathcal{R} \mathfrak{e} \lbrace s \rbrace < -\alpha $
8 $ \frac{t^{n-1}}{(n-1)!}e^{-\alpha t}u(t) $ $ \frac{1}{(s+\alpha )^{n}} $ $ \mathcal{R} \mathfrak{e} \lbrace s \rbrace > -\alpha $
9 $ -\frac{t^{n-1}}{(n-1)!}e^{-\alpha t}u(-t) $ $ \frac{1}{(s+\alpha )^{n}} $ $ \mathcal{R} \mathfrak{e} \lbrace s \rbrace < -\alpha $
10 $ \,\!\delta (t - T) $ $ \,\! e^{-sT} $ $ All\,\, s $
11 $ \,\![cos( \omega_0 t)]u(t) $ $ \frac{s}{s^2+\omega_0^{2}} $ $ \mathcal{R} \mathfrak{e} \lbrace s \rbrace > 0 $
12 $ \,\![sin( \omega_0 t)]u(t) $ $ \frac{\omega_0}{s^2+\omega_0^{2}} $ $ \mathcal{R} \mathfrak{e} \lbrace s \rbrace > 0 $
13 $ \,\![e^{-\alpha t}cos( \omega_0 t)]u(t) $ $ \frac{s+\alpha}{(s+\alpha)^{2}+\omega_0^{2}} $ $ \mathcal{R} \mathfrak{e} \lbrace s \rbrace > -\alpha $
14 $ \,\![e^{-\alpha t}sin( \omega_0 t)]u(t) $ $ \frac{\omega_0}{(s+\alpha)^{2}+\omega_0^{2}} $ $ \mathcal{R} \mathfrak{e} \lbrace s \rbrace > -\alpha $
15 $ u_n(t) = \frac{d^{n}\delta (t)}{dt^{n}} $ $ \,\!s^{n} $ $ All\,\, s $
16 $ u_{-n}(t) = \underbrace{u(t) *\dots * u(t)}_{n\,\,times} $ $ \frac{1}{s^{n}} $ $ \mathcal{R} \mathfrak{e} \lbrace s \rbrace > 0 $



  • (1)$ \delta(t) \leftrightarrow 1 $, for all s
  • (2)$ \ u(t) \leftrightarrow \frac{1}{s} $, for Re{s} > 0
  • (3)$ \ -u(-t) \leftrightarrow \frac{1}{s} $, for Re{s} < 0
  • (4)$ \frac{t^{n - 1}}{(n - 1)!}u(t) \leftrightarrow \frac{1}{s^{n}} $, for Re{s} > 0
  • (5)$ - \frac{t^{n - 1}}{(n - 1)!}u(-t) \leftrightarrow \frac{1}{s^{n}} $, for Re{s} < 0
  • (6)$ \ e^{\alpha t }u(t) \leftrightarrow \frac{1}{s + \alpha} $, for Re{s} > $ \ - \alpha $
  • (7)$ \ -e^{\alpha t }u(-t) \leftrightarrow \frac{1}{s + \alpha} $, for Re{s} < $ \ - \alpha $



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