紫吕洗发水有几种:求证:sin(α+β)sin(α-β)=sin²α-sin²β
来源:百度文库 编辑:神马品牌网 时间:2024/08/27 05:54:28
sin(α+β)sin(α-β)
=[sinαcosβ+cosαsinβ][sinαcosβ-cosαsinβ]
=[sinαcosβ]^2-sinαcosβcosαsinβ+cosαsinβsinαcosβ-[cosαsinβ]^2
=[sinαcosβ]^2-[cosαsinβ]^2
=[sinα]^2[1-(sinβ)^2]-[1-(sinα)^2][sinβ]^2
=[sinα]^2-[sinα]^2(sinβ)^2-[sinβ]^2+(sinα)^2][sinβ]^2
=[sinα]^2-[sinβ]^2
求证:sin(α+β)sin(α-β)=sin²α-sin²β
若α,β为锐角,且tanα=(sinβ-cosβ)/sinβ+cosβ,求证:sinβ-cosβ√2sinα.
已知:tan(α+β)=2tanα。求证:3sinβ=sin(2α+β)。
求解:3sinβ=sin(2α+β),求证tan(α+β)=2tanα
已知3sinβ=sin(2α+β) 求证tan(α+β)=2tanα
已知tan^2α=2tan^2β+1,求证sin^2β=2sin^2α-1
已知tan^2α=2tan^2β+1,求证sin^2β=2sin^2α-1
已知sinα=m sin(α+2β), |m|<1,求证tan(α+β)=(1+m)/(1-m)tanβ
以知cos(a+β )=-1,求证sin(2a+β )+sinβ=0
求证sin(5π/6-β)+sin(5π/6+β)=cosβ