1、cos(-17/4π)=cos(17π/4)=cos(17π/4-4π)=cos(π/4)=√2/2
6、sin(-26π/3)=sin(-26π/3+8π)=sin(-2π/3)=-sin(2π/3)=-√3/2
5、cos1615°8'=cos(1615°8'-4*360°)=cos175°8'=0.0848
4、cos(-1751°36')=cos(-1751°3...
用诱导公式求下列三角函数的值
1、cos(-17/4π)=cos(17π/4)=cos(17π/4-4π)=cos(π/4)=√2/2
6、sin(-26π/3)=sin(-26π/3+8π)=sin(-2π/3)=-sin(2π/3)=-√3/2
5、cos1615°8'=cos(1615°8'-4*360°)=cos175°8'=0.0848
4、cos(-1751°36')=cos(-1751°3...