Question

设集合M={x|2sinx>=1,0<=x<=π}，N={x|cosx<=1/2,0<=x<=π},求M∩N

Answer 1

M={x|2sinx>=1,0<=x<=π}={x|sinx>=1/2,0<=x<=π}={x|π/6<=x<=5π/6}
N={x|cosx<=1/2,0<=x<=π}={x|π/3 <=x <=π}

所以M∩N={x|π/3 <=x <=5π/6}

Answer 2

M=【π/6，5π/6】 N=【根号3π/2，π】
M∩N=【根号3π/2，5π/6】

Answer 3

解：M不就是{x:π/6≤x≤5π/6},N={x:π/3≤x≤π},
所以M∩N ={x:π/3≤x≤5π/6}。

Answer 4

函数有问题！