for the Sum/Difference Identities :

sin(x + t) = sin x cos t + cos x sin t
and
sin(x - t) = sin x cos t - cos s sin t

I have a question is it fine to write them like this: sin(x + t) = sin x cos t + sin t cos x or sin(x - t) = sin x cos t - sin s cos x ?

I know it's basically the same thing, but why do people even flip flop the last two?

yes it's fine to write them that way. trig functions multiplied together are commutative
it's just how people remember them/learned them/etc.

yeah, that's what I thought. Just threw me off seeing examples with them in different spots compared to what I had seen them.
thanks

This post was edited by holyspawn on Jul 8 2013 09:02am