Periodic  function:
                                A periodic function  must have the characteristic of
must have the characteristic of  where
where  is the period.
is the period.
                                 Horizontal shift of a function:
                                The graph of  is the graph of
is the graph of  shifted horizontally by a units.
shifted horizontally by a units.
                                 Vertical  stretching of a function:
                                The graph of  is the graph of
is the graph of  stretched vertically by a units.
stretched vertically by a units.
                                 Horizontal  shrinking of a function:
                                The graph of  is the graph of
is the graph of  shrunk horizontally by a units..
shrunk horizontally by a units..
                                 Reflection  and vertical shift of a function: 
                                The graph of  is the reflection of the graph
is the reflection of the graph  about x-axis.
about x-axis.
                                The graph of  is the graph of
is the graph of  shifted vertically by a units.
shifted vertically by a units.
                                Sinusoidal  functions: 
                                Functions whose equations satisfy  .
.
                                 Amplitude: 
                                A nonnegative scalar measure of the magnitude of sinusoidal  functions.
                                 Period: For a sinusoidal function  the absolute value of  is the period of the
 the absolute value of  is the period of the  sinusoidal function.
 sinusoidal function.
                                Phase shift of a sinusoidal  function:
                                For a sinusoidal function  the value of
 the value of  is the phase shift of  the sinusoidal function.
 is the phase shift of  the sinusoidal function.