• 2022-06-07
    18030f8be32b306.png是柱体[img=288x27]18030f8bee78404.png[/img]的表面(外侧), 则第二类曲面积分[img=169x48]18030f8bf907060.png[/img]等于
    A: [img=20x18]18030f8c0194900.png[/img]
    B: [img=34x20]18030f8c0a39b17.png[/img]
    C: [img=20x18]18030f8c13079b1.png[/img]
    D: [img=34x20]18030f8c1ad509e.png[/img]
    E: [img=20x18]18030f8c22b27b1.png[/img]
    F: [img=34x20]18030f8c2c6e934.png[/img]
    G: [img=20x18]18030f8c341d2bf.png[/img]
    H: [img=34x20]18030f8c3bfdc47.png[/img]
  • A

    内容

    • 0

      设随机变量X的概率密度为f(x),则f(x)一定满足( ). A: 0≤f(x)≤1 B: [img=183x53]1803b451bb3373a.png[/img] C: [img=133x51]1803b451c807078.png[/img] D: f(+∞)=1

    • 1

      若f(x)+f(-x)=0, 则[img=95x39]17da608af452d96.jpg[/img]. 若f(x)=f(-x), 则 [img=170x38]17da60541207426.jpg[/img]

    • 2

      令F(x):x是有理数,G(x):x是实数。将命题“所有的有理数都是实数,但有的有实数不是有理数”符号化为() 未知类型:{'options': ['17e0a83a4157352.jpgx(F(x)∧G(x))∧[img=8x14]17e0a83a35505d4.jpg[/img]x(G(x)[img=14x9]17e0a73094b5dcf.jpg[/img][img=10x11]17e0a839b915354.jpg[/img]F(x))', ' [img=8x14]17e0a83a4157352.jpg[/img]x(F(x)[img=14x9]17e0a73094b5dcf.jpg[/img]G(x))∧[img=8x14]17e0a83a35505d4.jpg[/img]x(G(x)∧[img=10x11]17e0a839b915354.jpg[/img]F(x))', ' [img=8x14]17e0a83a4157352.jpg[/img]x(F(x)∧G(x))∧[img=8x14]17e0a83a35505d4.jpg[/img]x(G(x)∧[img=10x11]17e0a839b915354.jpg[/img]F(x))', ' [img=8x14]17e0a83a4157352.jpg[/img]x(F(x)[img=14x9]17e0a73094b5dcf.jpg[/img]G(x))∧[img=8x14]17e0a83a35505d4.jpg[/img]x(G(x)[img=14x9]17e0a73094b5dcf.jpg[/img][img=10x11]17e0a839b915354.jpg[/img]F(x))'], 'type': 102}

    • 3

      180385778c22544.png是平面曲线[img=100x30]1803857795336d7.png[/img]从A(-2, 0)到B(2, 0)的曲线段,则[img=217x48]18038577a0a7de2.png[/img]等于 A: [img=34x20]18038577aa26824.png[/img] B: [img=20x18]18038577b299ef3.png[/img] C: [img=20x18]18038577ba3f2ee.png[/img] D: [img=34x20]18038577c23e003.png[/img] E: 0 F: [img=20x18]18038577cbc02c5.png[/img] G: [img=34x20]18038577d40831f.png[/img]

    • 4

      设随机变量X服从均值为2的指数分布,X的分布函数为F(x),数学期望为E(X),方差为D(X),则以下结果正确的是 A: [img=128x28]1802d3b369ab5fe.png[/img] B: D(X)=4 C: P(X<2︱X>1)=F(1) D: P(X>2︱X>1)= F(1) E: [img=112x27]1802d3b372fb534.png[/img] F: D(X)=E(X) G: P(X≤2︱X>1)= F(2) H: [img=82x27]1802d3b37bbbf05.png[/img]