The vectors are .
(Write magnitude of u)
(Apply dot product: )
(Substitute )
(Simplify)
The magnitude of u is .
![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=67e05ed211c11afbbc04aa764b113857.png\")
.![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=eba07f66983587f4a29ea6d021ff8e12.png\")
(Write magnitude of u)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=1ca5439deef44eb0203e65601c86bd4f.png\")
(Apply dot product: ![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=da40c8476e1582ae7285127ef6d82ec6.png\")
)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=4bc2ff44a6dcc610b6fd518897e553c9.png\")
(Substitute ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=62b79c2951935721635add3727b95bad.png\")
)![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=6f00f1dd91dfe9b1539ab392799b7d70.png\")
(Simplify)![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=ef6f3f391b43f47b546e6c432825f10f.png\")
.