sin110sin20/(cos155)2-(sin155)2
sin110sin20/(cos155)2-(sin155)2
【单选题】sin ( α+β ) = A. sinαcosβ-cosαsinβ B. cosαsin β-sin αcos β C. sinαcosβ+cosαsinβ D. cos αcos β-sin α sin β
【单选题】sin ( α+β ) = A. sinαcosβ-cosαsinβ B. cosαsin β-sin αcos β C. sinαcosβ+cosαsinβ D. cos αcos β-sin α sin β
【单选题】设y=sin(cos(x)),求 结果为:(本题10.0分) A. cos(cos(x))*cos(x)+ sin(cos(x))*sin(x)^2 B. - cos(cos(x))*cos(x) - sin(cos(x))*sin(x)^2 C. - cos(cos(x))*cos(x)^2 - sin(cos(x))*sin(x)^2 D. - cos(cos(x))*cos(x) ^2- sin(cos(x))*sin(x)
【单选题】设y=sin(cos(x)),求 结果为:(本题10.0分) A. cos(cos(x))*cos(x)+ sin(cos(x))*sin(x)^2 B. - cos(cos(x))*cos(x) - sin(cos(x))*sin(x)^2 C. - cos(cos(x))*cos(x)^2 - sin(cos(x))*sin(x)^2 D. - cos(cos(x))*cos(x) ^2- sin(cos(x))*sin(x)
cos(x)*cos(x/2)*cos(x/4)*cos(x/8).cos(x/(2^(n-1))
cos(x)*cos(x/2)*cos(x/4)*cos(x/8).cos(x/(2^(n-1))
155
155
\(设f(x,y,z)=\frac{x\cos y+y\cos z+z\cos x}{1+\cos x+\cos y+\cos z},则df|_{(0,0,0)}=(\,)\)
\(设f(x,y,z)=\frac{x\cos y+y\cos z+z\cos x}{1+\cos x+\cos y+\cos z},则df|_{(0,0,0)}=(\,)\)
sin(α-β)cosβ+cos(α-β)sinβ=( ) A: sin(α-2β) B: cos(α-2β) C: sinα D: cosα
sin(α-β)cosβ+cos(α-β)sinβ=( ) A: sin(α-2β) B: cos(α-2β) C: sinα D: cosα
【计算题】已知sinα+cosα=1,求:(1)sinαcosα; (2)sin α-cos α; (3)sin α-cos α
【计算题】已知sinα+cosα=1,求:(1)sinαcosα; (2)sin α-cos α; (3)sin α-cos α
已知向量a=(2,2,1),则a的方向余弦为(). A: cosα=2/3,cosβ=2/3,cosγ=1/3 B: cosα=2/5,cosβ=2/5,cosγ=1/5
已知向量a=(2,2,1),则a的方向余弦为(). A: cosα=2/3,cosβ=2/3,cosγ=1/3 B: cosα=2/5,cosβ=2/5,cosγ=1/5
已知sinα+sinβ+sinγ=0，cosα+cosβ-cosγ=0，则cos(α-β)的值是[ ]
已知sinα+sinβ+sinγ=0，cosα+cosβ-cosγ=0，则cos(α-β)的值是[ ]