Trigonometric Identities - Math.com - World of Math Online
cos ^2 (x) = 1/2 + 1/2 cos(2x) sin x - sin y = 2 sin( (x - y)/2 ) cos( (x + y)/2 ) cos x - cos y = -2 sin( (x - y)/2 ) sin( (x + y)/2 ) Trig Table of Common Angles angle 0 30 45 60 90 sin ^2 (a) 0/4 1/4 2/4 3/4 4/4 cos ^2 (a) 4/4 3/4 2/4 1/4 0/4 tan Given...