The expression is .
Rewrite the expression as .
Apply the product rule of limits.
.
Apply special trigonometric limits and .
![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=d042b9b5a4a317a1ccc5a2c5e8c93f5c.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=b8173d1160241798817b5b85d161cfc8.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=385ed64005ae9c5c3a0e7462399c395a.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=0ed8351fd8decd0d91931ced2c34dc19.png\")
and ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=17054ad8bf183d796ce6677af49a9e16.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=5b65b0ed83a88e821c652234b0346412.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=27826b958946345374624f5bab2ff9ca.png\")
. ![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=d8b191ea1ca15aa381917823e92988c4.png\")
.