TRIGONOMÉTRIE

IT. TRIGONOmÉTRIE.

Formules diverses; a, b, angles ;

Sin'a + cos'a = i Tang a colg a = i

rp sin a ^ cos a

Tang a = Cotga = -: —

° cos a ^ sin a

Seca r= Cosec a = -r

cos a sin a

Sec'a = 4 + tang'a Cosec^a = i 4- colg*a

Sin rt = d= -r=S^= Cosa=-^ *

V^i 4- tg*a v^i -h tg«rt

Sin (a + 6) = sin a cos 6 + sin b cos a Sin (a — 6) = sin a cos 6 — sin 6 cos a Cos (a 4- 6) = cos a cos 6 — sin a sin b Cos (a — 6) = cos a cos 6 -f- sjn a sin b

Sin 2a = 2 sin a cos a Cos 2a =: cos'a — sin^

Sin 3a = 3 sin a — 4 sin'» Cos 3a = 4 cos'a — 3 cos a

e- * i 4 /i — cos a ^4 j » /* Sm - a ==h W Cos - a = ±: i/ -