（1-sin^6α-cos^6α）/（sin^2α-sin^4α）的值
1-sin^6θ-cos^6θ=sin^2θ(1-sin^4θ)+cos^2θ(1-cos^4θ)=sin^2θ[sin^2θ(1-sin^2θ)+cos^2θ]+cos^2θ[cos^2θ(1-cos^2θ)+sin^2θ]=sin^2θ*cos^2θ*(1+sin^2θ)+sin^2θ*cos^2θ*(1+cos^2θ)=si...
举一反三
- 【计算题】已知sinα+cosα=1,求:(1)sinαcosα; (2)sin α-cos α; (3)sin α-cos α
- (1+sinθ)(1-sinθ)=______. A: 1-sinθ B: cos<sup>2</sup>θ C: 1-2sinθ+sin<sup>2</sup>θ D: cosθ E: 1
- 求微分方程[img=364x55]17da65386dfd612.png[/img]的通解； （ ） A: - cos(2*x)*exp(x)*(x/4 - sin(4*x)/16) + C23*cos(2*x)*exp(x) + C24*sin(2*x)*exp(x) B: (3*sin(2*x)*exp(x))/32 - (sin(6*x)*exp(x))/32 - cos(2*x)*exp(x)*(x/4 - sin(4*x)/16) + C23*cos(2*x)*exp(x) + C24*sin(2*x)*exp(x) C: - sin(4*x)/16) + C23*cos(2*x)*exp(x) + C24*sin(2*x)*exp(x) D: (sin(6*x)*exp(x))/32 - cos(2*x)*exp(x)*(x/4 - sin(4*x)/16) + C23*cos(2*x)*exp(x) + C24*sin(2*x)*exp(x)
- sinα-cosα=m求sin^4α+cos^4α的值
- sin(α-β)cosβ+cos(α-β)sinβ=( ) A: sin(α-2β) B: cos(α-2β) C: sinα D: cosα
内容
- 0
已知sin（α+β）=2/1,sin（α-β）=3/1求证：sinαcosβ=5cosαsinβ
- 1
级数sin(π/6)+sin(2π/6)+sin(3π/6)+…收敛
- 2
已知sin(3派+@)=1/3,求cos(派+@)/cos@[cos(派-@)-1]+cos(@-2派)/sin(@-3派/2)cos(@-派)-sin(3派/2+@)的值
- 3
【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
- 4
设\(z = {e^{x - 2y}}\)，而\(x = \sin t\)，\(y = {t^3}\)，则全导数\( { { dz} \over {dt}} = \) A: \({e^{\sin t - {t^3}}}(\cos t - 6{t^2})\) B: \({e^{\sin t - 2{t^3}}}(\sin t - 6{t^2})\) C: \({e^{\cos t - 2{t^3}}}(\cos t - 6{t^2})\) D: \({e^{\sin t - 2{t^3}}}(\cos t - 6{t^2})\)