sin(a+b)
sinacosb + cosasinb
sin(a-b)
sinacosb - cosasinb
cos(a+b)
cosacosb - sinasinb
cos(a-b)
cosacosb + sinasinb
tg(a+b)
tga+tgb/1-tga*tgb
tg(a-b)
tga-tgb/1+tga*tgb
ctg(a+b)
ctga*ctgb - 1/ctga+ctgb
ctg(a-b)
ctga*ctgb + 1/ctga-ctgb
sin2a
2sina*cosa
cos2a
cos^2-sin^2
tg2a
2*tga/1-tg^2a
ctg2a
ctg^2-1/2*ctga
cos a/2
+- sqrt(1+cosa/2)
sin a/2
+- sqrt(1-cosa/2)
tg a/2
+- sqrt(1-cosa/1+cosa)
ctg a/2
+- sqrt(1+cosa/1-cosa)
sina*cosb
1/2[sin(a+b)*sin(a-b)]
cosa*sinb
1/2[sin(a+b)-sin(a-b)]
cosa*cosb
1/2[cos(a+b)+cos(a-b)]
sina*sinb
1/2[cos(a+b)-cos(a-b)]
sina+sinb
2sin a+b/2 * cos a-b/2
sina-sinb
2sin a-b/2 * cos a+b/2
cosa+cosb
2cos a+b * cos a-b/2
cosa-cosb
-2sin a+b/2 * sin a-b/2