• 2022-05-26
    Given [img=214x47]18033783c242984.png[/img], then the initia value of the signal in the time domain, [img=44x26]18033783cb70806.png[/img] is ( )
    A: 1
    B: 1/2
    C: 1/4
    D: 2
  • D

    举一反三

    内容

    • 0

      求函数[img=148x49]17da6537a5eee98.png[/img]的导数; ( ) A: 1/(x^2*(2/x^2 + 1)) B: -1/(x^2*(2/x^2 + 1)) C: (x^2*(2/x^2 + 1)) D: -1/(x^2*(2/x^2 + 1))+2/x^2 + 1

    • 1

      不等式[img=114x24]18031ef38851681.png[/img]的解集是( ) A: {x|x<-1或x>2} B: {x|-1<x<2} C: {x|-2<x<1} D: {x|x<-2或x>1}

    • 2

      设随机变量[img=75x25]1802d5ab02ff46a.png[/img],且已知 E[(X - 1)(X + 2)] = 6,则[img=30x19]1802d5ab0aa816f.png[/img] A: 1 B: 2 C: 3 D: 4

    • 3

      设集合[img=235x35]17e0bf8ae8a8338.png[/img],则A∪B=( ) 未知类型:{'options': ['{x|-1≤x<;2}', ' [img=110x35]17e0bf8af4dd8ac.png[/img]', ' {x|x<;2}', ' {x|1≤x<;2}'], 'type': 102}

    • 4

      求不定积分[img=112x35]17da6538063a9e4.png[/img]; ( ) A: (x^4*log(x)^2)/4 + (x^4*(log(x) - 1/4))/ B: (x^4*log(x)^2)/4 - (x^4*(log(x) - 1/4))/8 C: (x^4*log(x)^2)/4 - (x^4*(log(x) - 1/4)) D: (x^4*log(x)^2)/4 + (x^4*(log(x) - 1/4))/8