(cos10度-sin40度)除以(sin10度-cos40度)=?
1个回答
展开全部
(cos10°-sin40°)/(sin10°-cos40°)
=(cos10°-sin(30°+10°))/(sin10°-cos(30°+10°))
=(cos10°-sin30°cos10°- cos30°sin10°))/(sin10°- cos30°cos10°+sin30°sin10°)
=(1/2 cos10°- cos30°sin10°))/（3/2 sin10°- cos30°cos10°）
= (sin30°cos10°- cos30°sin10°))/[ √3 (√3/2 sin10°-1/2cos10°)]
= sin(30°-10°)/ [ √3sin(10°-30°)]
=-√3/3.
=(cos10°-sin(30°+10°))/(sin10°-cos(30°+10°))
=(cos10°-sin30°cos10°- cos30°sin10°))/(sin10°- cos30°cos10°+sin30°sin10°)
=(1/2 cos10°- cos30°sin10°))/（3/2 sin10°- cos30°cos10°）
= (sin30°cos10°- cos30°sin10°))/[ √3 (√3/2 sin10°-1/2cos10°)]
= sin(30°-10°)/ [ √3sin(10°-30°)]
=-√3/3.
已赞过
已踩过<
评论
收起
你对这个回答的评价是？
推荐律师服务：
若未解决您的问题，请您详细描述您的问题，通过百度律临进行免费专业咨询
