jika 1/2 Π (phi)

π = 180
90 < x < 180 (kuadran 2)
sin x = 1/3
sisi depan 1
sisi miring 3
sisi samping √8 = 2√2

tan x = depan/samping
= -1/2√2 (rasionalkan)
= -1 / 2√2 × √2/√2
= -√2 / (2.2)
= -√2 / 4
= -¼√2