Laplace Transform Properties

In this topic, you study the Laplace Transform Properties as Linearity, Time Scaling, Time Shifting, Frequency Shifting, Time differentiation, Time integration, Time Reversal, Convolution in time and Multiplication in time.


Linearity
if

\[a{f_1}(t) \leftrightarrow a{F_1}(s)\]

\[b{f_2}(t) \leftrightarrow b{F_2}(s)\]

Then

\[a{f_1}(t){\text{ }}+{\text{ }}b{f_2}(t) \leftrightarrow a{F_1}(s){\text{ }} + {\text{ }}b{F_2}(s)\]

Time Scaling

if

\[f(t) \leftrightarrow F(s)\]

Then

\[f(at) \leftrightarrow \frac{1}{{\left| a \right|}}F\left( {\frac{s}{a}} \right)\]

Time Shifting

if

\[f(t) \leftrightarrow F(s)\]

Then

\[f(t – {t_0}) \leftrightarrow F({s}){e^{ – s {t_0}}}\]

Frequency Shifting

if

\[f(t) \leftrightarrow F(s )\]

Then

\[f(t){e^{{a}t}} \leftrightarrow F(s{} – {a})\]

Time differentiation

if

\[f(t) \leftrightarrow F(s)\]

Then

\[\frac{d}{{dt}}\left[ {f(t)} \right] \leftrightarrow s F(s)\]

Time integration

if

\[f(t) \leftrightarrow F(s)\]

Then

\[\int\limits_{ – \infty }^t {f(\tau )d\tau } \leftrightarrow \frac{1}{{s}}F(s)\]

Time Reversal

if

\[f(t) \leftrightarrow F(s)\]

Then

\[f( – t) \leftrightarrow F( – s )\]

Convolution in time

if

\[{f_1}(t) \leftrightarrow {F_1}(s)\]

\[{f_2}(t) \leftrightarrow {F_2}(s)\]

Then

\[{f_1}(t)*{f_2}(t) \leftrightarrow {F_1}(s){F_2}(s)\]

Multiplication in time

if

\[{f_1}(t) \leftrightarrow {F_1}(\omega )\]

\[{f_2}(t) \leftrightarrow {F_2}(\omega )\]

Then

\[{f_1}(t){f_2}(t) \leftrightarrow \frac{1}{{2\pi j}}\left[ {{F_1}(s)*{F_2}(s )} \right]\]

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