Trigonometric ratios .
When , then is not true.
Hence the statment of Alisa is false and trey statement is correct.
The statment of Trey is true.
![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=2cd9edc167b462744a2149a7f49dcbde.png\")
.![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=2cd9edc167b462744a2149a7f49dcbde.png\")
, then ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=552828e501f79d3573c8c62b08ec7736.png\")
is not true.![\"\"](\"/userfiles/image/steps_images/step2.JPG\")