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问题: 高1数学题6

α=派/24
求(sinα/cos4αcos3α)+(sinα/cos3αcos2α)+(sinα/cos2αcosα)+(sinα/cosα)

解答:

(sinα/cos4αcos3α)+(sinα/cos3αcos2α)+(sinα/cos2αcosα)+(sinα/cosα)
= (sinα/cos3α)[1/cos4α + 1/cos2α]+(sinα/cosα)[1 + 1/cos2α]
= (sin2α/cos2α)[1 + 1/cos4α]
= (sin2α/cos2α)[2(cos2α)^2/cos4α]
= tg4α
= tg(4*派/24)
= (genhao3)/3