sin50(1+根下3tan10)等于多少 - 知识问答

sin50(1+根下3tan10)等于多少

1个回答

sin50°(1+√3tan10°)
=2sin50°(1/2+√3/2tan10°)
=2sin50°(1/2cos10°+√3/2sin10°)/cos10°
=2sin50°(sin30°cos10°+cos30°sin10°)/cos10°
=2sin50°sin40°/cos10°
=2cos40°sin40°/cos10°
=sin80°/cos10°
=1
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