帮忙做一下这些题

来源：百度知道 编辑：UC知道 时间：2024/05/23 12:11:53
sin3π=？sin18π=？cos5π=?cos25π=?sin9π/2=?sin13π/3=?cos47π/2=?
cos103π/4=?tan37π/6=?sin(-11π/6)=?cos(-17π/3)=?tan(-17π/6)=?
最好有步骤

sin3π=sin(2π+π)=sinπ=0
sin18π=0
cos5π=cos(4π+π)=cosπ=-1
cos25π=cos(24π+π)=cosπ=-1
sin9π/2=sin(4π+π/2)=sinπ/2=1
sin13π/3=sin(4π+π/3)=sinπ/3=√3/2
cos47π/2=cos(22π+π+π/2)=-cosπ/2=0

cos103π/4=cos(26π-π/4)
=cos(-π/4)=cosπ/4=√2/2

tan37π/6=tan(6π+π/6)=√3/3
sin(-11π/6)=sin(-2π+π/6)=sinπ/6=1/2
cos(-17π/3)=cos(-6π+π/3)=cosπ/3=1/2
tan(-17π/6)=tan(-6π+π/3)=tanπ/3=√3