1/sin10-根号3/cos10 sin50(1+根号3tan10)
1个回答
展开全部
①1/sin10-根号纤脊辩3/cos10
原式=(cos10-√3sin10)/sin10cos10
=4[(1/2)cos10-(√3/2)sin10]/2sin10cos10
=4(cos10cos60-sin60sin10)/sin20
=4cos(10+60)/sin20
=4cos70/sin20
=4sin20/野肆sin20
=4
②sin50(1+根号3tan10)
原式=sin50°*[1+根号3(sin10°/cos10°)]
=sin50°*[(cos10°+根号3sin10°)/毁缺cos10°]
=sin50°*[2sin(30°+10°)/cos10°]
=(2sin50°*sin40°)/cos10°
=(2cos40°*sin40°)/cos10°
=sin80°/cos10°
=cos10°/cos10°
=1
原式=(cos10-√3sin10)/sin10cos10
=4[(1/2)cos10-(√3/2)sin10]/2sin10cos10
=4(cos10cos60-sin60sin10)/sin20
=4cos(10+60)/sin20
=4cos70/sin20
=4sin20/野肆sin20
=4
②sin50(1+根号3tan10)
原式=sin50°*[1+根号3(sin10°/cos10°)]
=sin50°*[(cos10°+根号3sin10°)/毁缺cos10°]
=sin50°*[2sin(30°+10°)/cos10°]
=(2sin50°*sin40°)/cos10°
=(2cos40°*sin40°)/cos10°
=sin80°/cos10°
=cos10°/cos10°
=1
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