问题
填空题
不等式cosx+
|
答案
不等式cosx+
≤0 即 cosx≤-1 2
,∴2kπ+1 2
≤x≤2kπ+2π 3
,k∈z.4π 3
故不等式的解集为 [2kπ+
,2kπ+2π 3
],k∈z,4π 3
故答案为[2kπ+
,2kπ+2π 3
],k∈z.4π 3
不等式cosx+
|
不等式cosx+
≤0 即 cosx≤-1 2
,∴2kπ+1 2
≤x≤2kπ+2π 3
,k∈z.4π 3
故不等式的解集为 [2kπ+
,2kπ+2π 3
],k∈z,4π 3
故答案为[2kπ+
,2kπ+2π 3
],k∈z.4π 3
Passage 3
Which of the following is not true about the Nokia-Yahoo deal a. It covers the mid-priced cell phone. b. It is dominated by high-priced cell phone. c. Some Nokia models have been available in the market in different areas. d. The deal was first announced in January.