(cos40°+sin50°(1+√3tan10°))/sin70°√(1+cos40°)
问题描述:
(cos40°+sin50°(1+√3tan10°))/sin70°√(1+cos40°)
答
[cos40°+sin50°(1+√3tan10°)]/[sin70°√(1+cos40°)]=[cos40°+sin50°×(tan60°-tan10°)/tan50°]/sin70°(√2)cos20°=[cos40°+(tan60°-tan10°)cos50°]/sin70°(√2)cos20°=[cos40°+√3cos50°-t...