tan15°+cot15°=?好嘞.最后一题嘞.求 - 知识问答

tan15°+cot15°=?好嘞.最后一题嘞.求简要过程~~~

4个回答

tan15+cot15
=sin15/cos15+cos15/sin15
=(sin²15+cos²15)/(sin15cos15)
=1/[(1/2)sin(2×15)]
=2/sin30
=2/(1/2)
=4

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