How can if its maximum value is 1.
In this post ...
Double Angle Equations!
...you were requested to post specific problems rather than cryptic references to double angle problems. Now it seems you're making up stuff, because you really don't know what you're doing.
Post a specific problem from a text or as given by your instructor.
But please let us know what the actual problem statements are. You have been asked to clarify a question before.