解不等式组
1-tanx≥0 ①
-1-2sinx≥0 ②
由①得 x∈(kπ-π/2,kπ+π/4]
由②得 x∈[2kπ+7π/6,2kπ+11π/6]
∴x∈[2kπ+3π/2,2kπ+7π/4],k∈Z