公主灵儿
春芽
共回答了15个问题采纳率:100% 举报
根号6
原式=[2sin50+2sin10/cos10(1/2 *cos10+根号3/2* sin10)]*根号2sin80
=[2sin50+2sin10 cos10 (sin30cos10+cos30 sin10)]*根号2sin80
=(2sin50+2sin10cos10sin40)*根号2sin80 (sin 40=cos 50)
=2/cos10 (sin50 cos10+ sin10 cos 50)*根号2sin80 (sin 80=cos 10)
=2* sin60* 根号2
=根号6
1年前
10