Question

cos、sin、tan的三角函数值 急！！！

sinx<1/2 cosx≥-√3/2 tanx<1 sinx≥-√3/2 cosx<1/2 tanx≥-√3
求角的集合、、

Answer 1

sinx<1/2 (2k-1)π-π/6<x<2kπ+π/6
cosx≥-√3/2 (2k-1)π+π/6=<x<=(2k+1)π-π/6
tanx<1 kπ-π/2<x<kπ+π/4
sinx≥-√3/2 2kπ-π/3=<x<=(2k+1)π+π/3
cosx<1/2 2kπ+π/3<x<(2k+2)π-π/3
tanx≥-√3 kπ-π/3=<x<=kπ+π/2
以上k都为任意整数。