写出与下列各角终边相同的角的集合S,并且把S中适合不等式-2π≤a<4π的元素写出来: (1)4 (2)-2⼀3

2025-06-22 07:17:25
推荐回答(2个)
回答1:

1、π是180°,4比π大点。终边相同的角的集合S=4+2kπ,k为整数。-2π≤a<4π之间,
a=4-2π,或4或4+2π
2、S=2kπ-2π/3,-2π≤a<4π之间,a=-2π/3或4π/3或10π/3
3、S=2kπ+12π/5,-2π≤a<4π之间,a=-8π/5或2π/5或12π/5
4、S=2kπ,-2π≤a<4π之间,a=-2π或0或2π

回答2:

①S=2Kπ+4 (k∈Z)
π<4<3π/2 符合的有:-2π+4,4,2π+4
②S=2Kπ-2π/3 (k∈Z)
符合的有:-2π/3,4π/3,10π/3
③S=2Kπ+12π/5 (k∈Z)
符合的有:-8π/5,2π/5,12π/5
④S=2Kπ (k∈Z)
符合的有:-2π,0,2π