cos d =-0.6, П<a<3П/2
sin^2 a = 1 — cos^ a = 1 — 0,36 = 0,64
sin a = -0,8 (III четверть)
1 + tg^2 a = 1/cos^2 a
tg^2 a = (1/cos^2 a) — 1 = 1/(0,36) — 1 = 64/36 = 16/9
tg a = 4/3 (III четверть)
ctg a = 1/tg a = 3/4(III четверть)
sec a = 1/cos a = -5/3
cosec a = 1/sin a = -5/4