Question

比较sin(-879),tan(-33π/8),cos(-13π/10)的大小,

Answer 1

sin(-879°)=-sin879°=-sin(2*360°+159°)=-sin(159°)=-sin(180°-21°)=-sin21° ；

tan(-33π/8)=-tan(4π+π/8)=-tan(π/8)=-tan22.5°=-0.4142；

cos(-13π/10)=cos(13π/10)=cos(π+3π/10)=-cos(3π/10)=-cos54°=-0.5878.

比较结果：sin(-879°)＞tan(-33π/8)＞cos(-13π/10).