The expression is .
(Rewrite )
(Apply sum 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=25c1d8c03239c079a93cfd1d00823890.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=0af7eac2441d8fb4f49ba293d685947c.png\")
(Rewrite ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=af721e594fc13df431600172689d05fe.png\")
)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=a43c750fa5f6f0992daddbd01c13a050.png\")
) ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=5ae896cf2bdb52ea1619c02267cde6b8.png\")
![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step2.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=0abe75723b7eea3e42ccc84a4f6d867b.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=546ba823c4ccfc1dcdbdfc19b03d79c3.png\")
.