第1个回答 2011-02-14
1.
sin750°=sin(2*360°+30°)=sin30°=1/2
cos750°=cos30°=√3/2
tan750°=tan30°=√3/3
2.
sin17π/4=sin(4π+π/4)=sinπ/4=√2/2
cos17π/4=cosπ/4=√2/2
tan17π/4=tanπ/4=1
3.
sin-11π/6=sin(-2π+π/6)=sinπ/6=1/2
cos-11π/6=cosπ/6=√3/2
tan-11π/6=tanπ/6=√3/3
4.
sin-1020°=sin(-1020°+3*360°)=sin60°=√3/2
cos-1020°=cos60°=1/2
tan-1020°=tan60°=√3