Yes it is true,Every sine function of the form can be written as a cosine function of the form along with some phase shift.
Since the graph of the cosine function is horizintal shift of the sine function .
Yes it is true.
![\"\"](\"/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"http://www.mathskey.com/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=2432cb84d63005d7c7a2ac1795a7f9ff.png\")
can be written as a cosine function of the form ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=ce4e463f2e9c23ac7c38d66b0eaa48d6.png\")
along with some phase shift.![\"\"](\"/userfiles/image/steps_images/solution.JPG\")