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
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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
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
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
sin(派/3)+cos(2派/3)
=√3/2+(-1/2)
=(√3-1)/2
;tan(-派/3)+cos(7派/4)
=-√3+√2/2
sin(派/3)+cos(2派/3)
=sin(派/3)-cos(派/3)
=√3/2-1/2
tan(-派/3)+cos(7派/4)
=-tan(派/3)+cos(派/4)
=-√3+√2/2
1.sin(π/3)=√3/2
cos(2π/3) =-cos(π/3)=-0.5
sin(π/3)+cos(2π/3)=√3/2-0.5=(√3-1)/2
2.tan(-π/3)=-tan(π/3)=-√3
cos(7π/4)=cos(2π-π/4)=cosπ/4=√2/2
tan(-π/3)+cos(7π/4)=-√3+√2/2
sin(π/3)+cos(2π/3)=sin(π/3)+cos(π-π/3)=sin(π/3)-cos(π/3)=√3/2-1/2=(√3-1)/2
tan(-π/3)+cos(7π/4)
=-tan(π/3)+cos(2π-π/4)
=-tan(π/3)+cos(-π/4)
=-tan(π/3)+cos(π/4)
=-√3+√2/2
sin(派/3)+cos(2派/3)
=√3/2+(-1/2)
=(√3-1)/2
;tan(-派/3)+cos(7派/4)
=-√3+√2/2
tan(-π/3)=-tan(π/3)=-√3
cos(7π/4)=cos(2π-π/4)=cosπ/4=√2/2
tan(-π/3)+cos(7π/4)=-√3+√2/2