\
The function is
.
\
Substitute
in
.
\
\
\
.
\
Since
,
the function
is an even function.
\
is an even function.
![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=51e12075656b9ae81b0eef09c162087f.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=04f12933e795f293176eac47763e240f.png\")
in .![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=1b81d580e6e828fc97164e21c4eac248.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=1db436817976e9f628a808347f91cfcd.png\")
. , the function is an even function.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
is an even function.