sin^2 + cos^2t = 1
(-15/17)^2 + cos^2t = 1
cos^2t = 1 - 225/289; cos^t = 64/289; cost = +-8/17; cost = 8/17; tgt = sint/cost; tgt = -15/17:8/17 = -15/8; ctgt = cost/sint = -8/15; cost = 8/17; tgt = -15/8; ctgt = -8/15

Ответы и объяснения

2013-12-10T17:54:12+00:00
Sint = 1/2
t = (-1)n arcsin 1/2 + πn, nEz
t = (-1)n π/6 + πn, nEz

cost = (корень)2/2
t = +- arccos корень2/2 + πn, nEz
t = +-π/4 + πn, nEz