作业帮(sin91)^2+(sin92)^2+……+(sin180)^2=?
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(sin91)^2+(sin92)^2+……+(sin180)^2=?
(sin91)^2+(sin92)^2+……+(sin180)^2=?
(sin91)^2+(sin92)^2+……+(sin180)^2=?
(sin91)^2+(sin92)^2+……+(sin180)^2
=(sin89)^2+(sin88)^2+……+(sin46)^2+(sin45)^2+(sin44)^2+……+(sin1)^2+(sin0)^2
=(sin89)^2+(sin88)^2+……+(sin46)^2+(sin45)^2+(cos46)^2+……+(cos89)^2
=[(sin89)^2+(cos89)^2]+……+[(sin46)^2+(cos46)^2]+(sin45)^2
=44*1+1/2
=89/2
sin(90+n)=cosn
sin(180-n)=sinn
cos=^2+sinn^2=1
原式===34+(根2)/2
(sin91)^2+(sin92)^2+……+(sin180)^2=?
sin91°＜sin92°,cos91°＜cos92°,tan91°＜tan92°,cot91°＜cot92°哪个是正确的?
Sin92=?三克油!
化简sin119 sin181 －sin91 sin29 等于
为什么sin91°等于cos91°?都在第几象限?
cos29°cos91°-sin91°sin29°=?RT
sin91度sin29度-cos91度cos29度
化简 sin119°sin181°-sin91°sin29°= 写个过程啊~
sinx+sinb+sin91度=0 ,cosx+cosb+cos91度＝0,求cos(x-b)
已知sinα+sinβ+sin91=0,cosα+cosβ+cos91=0,则cos(α-β)＝
已知sina+sinβ+sin91°=0,cosa+cosβ+cos91°=0则cos（a-β）=？
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