cos^2 (a+x) -sin^2 a=cos x * cos(2a+x)
precalc and trig - Reiny, Sunday, February 22, 2009 at 8:22pm
don't tell my I did all that work, and you didn't even look at it.
precalc and trig - hayden, Sunday, February 22, 2009 at 8:43pm
i posted a sorry. i posted this twice on that one. And i don't understand how RS=LS and thanks