hi

here are some of my favourite trig relationships, ive just copied them from one of my other posts. i always find these useful

cosA*cosA + sinA*sinA = 1
secA*secA = 1 + tanA*tanA
cosecA*cosecA = 1 + cotA*cotA
cosA*cosA = 0.5(1+cos2A)
sinA*sinA = 0.5(1-sin2A)
cos2A = cosA*cosA-sinA*sinA
sin2A = 2sinAcosA
tan2A = (2tanA)/(1-tanA*tanA)


a cosb + b sinb = R cos (b-a) where R = Ö(a*a + b*b) and cosa = a/R sina = b/R

ill post some of my favourite projectile ones latter, and perhaps some other pretty equations, but here are a few for you equation junkies out there. dont lie, i know your out there.

thanks
Matthew