已知tanα=-根号3,求sinα,cosα,
问题描述：
已知tanα=-根号3,求sinα,cosα,
答
∵tanα=-√3∴α=kπ-π/3(k是整数)故sinα=sin(kπ-π/3)=sin(kπ)*cos(π/3)-sin(π/3)*cos(kπ)=-(√3/2)*(-1)^k=(√3/2)*(-1)^(k+1)cosα=cos(kπ-π/3) ...