• 2022-06-19
    空间曲线[img=178x61]1803d4598610533.png[/img]在[img=31x23]1803d4598e7180e.png[/img]上的投影曲线的参数方程为( ).
    A: [img=409x29]1803d4599a3653d.png[/img]
    B: [img=340x29]1803d459a503bb0.png[/img]
    C: [img=354x29]1803d459b187bbe.png[/img]
    D: [img=351x29]1803d459bd69143.png[/img]
  • D

    内容

    • 0

      下列4个集合中是空集的是() A: {x|[img=18x22]1802f060e2f728f.png[/img]+1=0} B: {x|[img=18x22]1802f060e2f728f.png[/img]<-x} C: {x|[img=18x22]1802f060e2f728f.png[/img]=0} D: {x|[img=18x22]1802f060e2f728f.png[/img]-1=0}

    • 1

      下列4个集合中是空集的是() A: {x|[img=18x22]1803d021d498831.png[/img]+1=0} B: {x|[img=18x22]1803d021d498831.png[/img]<-x} C: {x|[img=18x22]1803d021d498831.png[/img]=0} D: {x|[img=18x22]1803d021d498831.png[/img]-1=0}

    • 2

      下列4个集合中是空集的是() A: {x|[img=18x22]1803d0240bcad39.png[/img]+1=0} B: {x|[img=18x22]1803d0240bcad39.png[/img]-x} C: {x|[img=18x22]1803d0240bcad39.png[/img]=0} D: {x|[img=18x22]1803d0240bcad39.png[/img]-1=0}

    • 3

      设X,Y为相互独立的随机变量,X在&#91;-1,1&#93;上服从均匀分布,Y服从参数为2的指数分布,则(X,Y)的联合密度f(x,y)为( ). A: [img=269x61]18034e69fa6ccc5.png[/img] B: [img=178x61]18034e6a0486f36.png[/img] C: [img=274x61]18034e6a0e8ff4a.png[/img] D: [img=277x73]18034e6a1a5c158.png[/img]

    • 4

      由[img=35x25]1803d355c182eb9.png[/img]上连续曲线y = f(x)及直线x =a,x= b(a <b)与x轴所围图形面积S=( ) A: [img=83x52]1803d355cabd312.png[/img] B: [img=95x53]1803d355d361a34.png[/img] C: [img=91x52]1803d355dc59dde.png[/img] D: [img=149x45]1803d355e4a0041.png[/img]