Question

求角19π/6的正弦,余弦,正切 帮忙写一下过程

Answer 1

19π/6=2π+π+π/6
所以
sin19π/6
=sin(2π+π+π/6)
=sin(π+π/6)
=-sinπ/6
=-1/2
cos19π/6
=cos(2π+π+π/6)
=cos(π+π/6)
=-cosπ/6
=-√3/2
tan19π/6
=tan(2π+π+π/6)
=tanπ/6
=√3/3