求(sin40°+cos10°)/cos20° =(cos50°+cos10°)/cos20°
来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/10/06 16:52:10
求(sin40°+cos10°)/cos20° =(cos50°+cos10°)/cos20°
(sin40°+cos10°)/cos20°
=【cos(π/2-40°)+cos10°】/cos20°
=(cos50°+cos10°)/cos20°
再问: 那(cos50°+cos10°)/cos20°=2cos30°cos20°/cos20°的过成了?
再答: ———— (cos50°+cos10°)=cos(30+20)+cos(30-20) ∴ cos50°+cos10°)/cos20° =【2cos(50+10)/2+cos(50-10)/2】/cos20 =2cos30°cos20°/cos20 【懒得打°了,希望不影响您=V=】
=【cos(π/2-40°)+cos10°】/cos20°
=(cos50°+cos10°)/cos20°
再问: 那(cos50°+cos10°)/cos20°=2cos30°cos20°/cos20°的过成了?
再答: ———— (cos50°+cos10°)=cos(30+20)+cos(30-20) ∴ cos50°+cos10°)/cos20° =【2cos(50+10)/2+cos(50-10)/2】/cos20 =2cos30°cos20°/cos20 【懒得打°了,希望不影响您=V=】
求cos20°cos10
数学函数化简题2cos10°-sin20°/cos20°=?sin40°+2cos70°/sin50°=?
cos20°cos10°+sin10°sin10°
化简(tan10°-根号3)*(cos10°/sin50°)*(2cos10°-sin20°/cos20°)
化简((cos20°/sin20°)cos10°)+根号3(sin10°tan70°)-2cos40°
化简cos10°根号下1-cos40°/sin20°根号下1+cos20°
(sin10°+sin20°)/(cos10°+cos20°)化简求值
代数式2cos10°−sin20°cos20°的值为( )
sin40°*(1-sin10°)/[sin10°*(cos20°)^2]
计算:(sin20°-sin40°)÷(cos20°-cos40°)
很简单的数学题求答案sin20°18',sin30°36‘18’‘,cos10.5°,cos20°18',cos30°3
sin40°cos10°-cos40°sin10°