Never; the graph of is a vertical line.
Therefore it will always fail the vertical line test, for any value of .
Never; it will always fail the vertical line test, for any value of .
![\"\"](\"/userfiles/image/steps_images/solution.JPG\")
![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=b2e53498cc30d9d358d484b27fad56ca.png\")
is a vertical line.![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=52257f1605fb2b790995dd69987af2c6.png\")
..