化简(tan10°—根号3)乘以cos10°/si - 知识问答

化简(tan10°—根号3)乘以cos10°/sin50°

1个回答

原式=(sin10°/cos10°—根号3)·cos10°/sin50°
=[sin10°-（根号3）·cos10°]·cos10°/sin50°
=[sin10°-（根号3）·cos10°]/sin50°
=2[sin10°cos60°-sin60°cos10°]/sin50°
=2sin(10°-60°)/sin50°
=-2

相关问题