Trigonometry Identities :D

I. Am. Nerd... Hear me "Nerdspeak" ;-D :-D There is definitely a plethora of "identities" in Trigonometry. For instance (but not confined to), there are the 'Pythagorean Identities', which are basically just numerous variations of the Pythagorean Theory itself, near-endlessly manipulated by the six Trigonometric functions. Then there be the 'Quotient Identities', which are basically the aforementioned functions dividing each other to equal still other seemingly unrelated functions. And then somewhere in there, there's my identity. I so love Math