\
The expression is
.
\
Apply sum-to-product formula:
\
\
\
(Simplify)
\
The expression is
.
![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=47f8d9d16684dcde0ea63a77ae6c34c4.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=c23a47e730e4533f9cf12590b80f3098.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=b885c02cfa70ff3239855c6b77a1094c.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=941b961ac2beb04d470636ee95d236b7.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=abcb4585372e558dd2d395d52406538c.png\")
(Simplify)![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=377778c5b53477b524ef4059efc86648.png\")
.