Sin (-23pi/4)tg19 pi/6

Question

Sin (-23pi/4)tg19 pi/6

Answer 1

Sin (-23π/4) · tg (19π/6) = sin (-24π/4 - π/4) · tg (18π/6 + π/6) =
= sin (-6π - π/4) · tg (3π + π/6) =  sin (- π/4) · tg (3π + π/6) =
=-0.5√2 · tg (π + π/6) = -0.5√2 · tg (π + π/6) = -0.5√2 · tg (π/6) =
= -0.5√2 ·√3 / 3 = - √6 /6 = -1/√6