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若sin(a+β)=1/5,sin(a-β)=3/5,则tana/tanβ
人气:435 ℃ 时间:2020-04-07 15:18:43
解答
sin(a+β)= sina cosβ +cosa sinβ = 1/5
sin(a-β)= sina cosβ -cosa sinβ = 3/5
解得
sina cosβ = 2/5
cosa sinβ = -1/5
做商
tana /tanβ= sina cosβ /cosa sinβ = -2
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