已知α∈(π/4,π/2)若sin2α=3/5则sinα-cosα=
人气:487 ℃ 时间:2020-02-03 10:41:29
解答
sin2α=2sinαcosα= 3/5
(sinα-cosα)2= 1-2sinαcosα=2/5
又α∈(π/4,π/2)
sinα大于cosα
所以sinα-cosα= 根号10/5
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