2sinx-cosx=0 求sin2x和 sin^2+sinxcosx

来源:学生作业帮助网 编辑:作业帮 时间:2024/07/09 03:40:23
2sinx-cosx=0 求sin2x和 sin^2+sinxcosx
x10 ED2 = Rab)aM8T9J!1?)1u!2s9nדP2Cqsw)uf(, ^gs@*5n9chԴ[u%jNWlXrNG

2sinx-cosx=0 求sin2x和 sin^2+sinxcosx
2sinx-cosx=0 求sin2x和 sin^2+sinxcosx

2sinx-cosx=0 求sin2x和 sin^2+sinxcosx
2sinx-cosx=0 2sin x=cos x tan x=sin x / cos x =1/2
sin2x =2 sin x cos x =(2 sin x cos x ) / (sin^2 x + cos^2 x )
=2tan x /(tan^2 x +1) =4/5
sin^2 x +sin x cos x =(sin^2 x +sin x cos x) / (sin^2 x + cos^2 x )
=(tan^2 x +tan x) / (tan^2 x +1)= 3/5