FORMULES TRIGONOMÉTRIQUES

Triangles rectilignes. — Formules générales.

a ^ b sinA~~ sinB a 5 = b 7 -\- c 2 — %bc cos A

: — — ~ = att= — rr •

sidC ^b

= (6-hc) 2 -4àccos 2 iA = (6 — c) a H-4^csinHA ==(6+c) 2 sin 2 ±A-h(6--r) 2 cosHA.

fl = ^cosC-f-ccosB, £ = ccosA-f-acosC, c = ûcosB-h^cosA.

Triangles obliquangles, — Cas m et IV.

. . j asKnBasftsûiA, . I asin j(B — C) = (£ — cjcosjA,

l4 ' { «cosB=c-*cosA. [ ' { £icosi(B— C) = (^+c)siniA.

sur

lA - Te

tangi(B-C) = tang(( ? -.45°)cotiA.

cosHA = £iZ^.

rfA = -«fB-rfC,

cotBrfB = ^ - — 4-cotArfA, de = sécB(<fa — cosCdfc — c sinBt/A).

dB = - {ainCdb — sinBrfc — à cosCtfA) , <& = cofifrtô + cosBdc 4- b sin (MA.

rfA = - cosécB (ûto — cosC*# — cosBdic).

^ = — - cot ArfA -h cotBrfB.

rfC = — rfA — tfB,

Triangles sphériques rectangles. — (ôcaB, ccoC).