The limit of the function is
.
The squeeze theorem :
\If
when
is near to
then
.
Use the squeeze theorem:
\Find the function
smaller than
and a function
greater than
, Such that
and
are approaches to
.
The range of sine function is
.
.
Multiply with
throughout the equation.

By the squeeze theorem
,
and
.
, then
.
.
Graph :
\Graph the functions on the same plane.
\(1) Draw the coordinate plane.
\(2) Graph the function
.
(3) Graph the function
.
(4) Graph the function
.

.