The expression is .
(Rewrite )
(Apply difference of angles formula: )
(The values of )
(Multiply)
(Simplify)
The exact value of .
![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=03b8f70275e308a850feea45853b4dc7.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=60e58d109d8188072ef44dcc82467d5c.png\")
(Rewrite ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=ba33ab39d7a78afb2598d991f6dd35c7.png\")
)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=0f53900357785a6cfbbc9c5d2eef3570.png\")
) ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=290a991d8aa2cb2af554a68e52e46aed.png\")
![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step2.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=753ed72330d1a8a490d3fcc27fc018da.png\")
)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=2547ae953fe50126588494f582595dd1.png\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=d9913e2cec4eae38f7a8652ce9ad53f8.png\")
(Multiply)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=686005760f8e86336342f04f4edc44b9.png\")
(Simplify)![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=8ec78d8829c175eada25f46a24ffeeca.png\")
.