sinx=1/2
当x∈[0,2π]时,
x=π/6,或x=5π/6
当x∈R时,
x=π/6+2kπ,或x=5π/6+2kπ,k∈Z
x的取值集合
｛x|x=π/6+2kπ,或x=5π/6+2kπ,k∈Z}