求下列各式的值:sin(派/3)+cos(2派/3) ;tan(-派/3)+cos(7派/4)
问题描述:
求下列各式的值:sin(派/3)+cos(2派/3) ;tan(-派/3)+cos(7派/4)
详细过程已知角a的终边在直线y=kx上若sina=2/更号5.cosa
答
sin(派/3)+cos(2派/3)
=√3/2+(-1/2)
=(√3-1)/2
;tan(-派/3)+cos(7派/4)
=-√3+√2/2