解:[2sin50°+sin10°(1+√3tan10°)]*√2(sin80°)*(sin80度)

2025-06-27 16:21:20
推荐回答(2个)
回答1:

[2sin50°+sin10°(1+√3tan10°)]*√2(sin80°)*(sin80度)
=[2sin50°*sin80°+sin10°*cos10°(cos10°+√3sin10°)/cos10°]*√2(sin80°)
=[2sin50°*sin80°+2sin10°(1/2cos10°+√3/2sin10°)]*√2(sin80°)
=[2sin50°*sin80°+2sin10°sin(30°+10°)]*√2(sin80°)
=[2sin50°*sin80°+2sin10°sin40°]*√2(sin80°)
=[2sin50°*cos10°+2sin10°cos50°]*√2(sin80°)
=2[sin60°]*√2(sin80°)
=√6sin80°

回答2:

√2sin²80°是根号下(2sin²80°),还是在(√2)×(sin²80°)?若是前者,
原式={2sin50°+sin10°[1+√3(sin10°/cos10°)]}×[√(2sin²80°)]
={2sin50°+sin10°[(cos10°+√3sin10°)/cos10°]}×[√(2sin²80°)]
={2sin50°+sin10°[2sin(10°+30°)/cos10°]}×[√(2sin²80°)]
=[2sin(90°-40°)+sin10°(2sin40°/cos10°)]×[√(2sin²80°)]
=[2cos40°+(2sin10°sin40°/cos10°)]×[√(2sin²80°)]
=[2(cos40°cos10°+sin10°sin40°)/cos10°]×[√(2sin²80°)]
=[2cos(40°-10°)/cos10°]×√[2sin²(90°-10°)]
=(2cos30°/cos10°)×√(2cos²10°)
=[(√3)/cos10°]×[(√2)×(cos10°)]
=√6
若是后者,步骤都一样,答案是(√6)×(cos10°)