• 2022-06-16
    函数y=log2(x2-9)的定义域是()
    A: (3,+∞)
    B: (-∞,-3)U(3,+∞)
    C: (-∞,-3)
    D: (-∞,-3]U[3,+∞)
  • B

    内容

    • 0

      用R程序编程求下列的值,正确的命令是 ( )[img=273x30]180398c76b70239.png[/img] A: x<-log(2);y<-log(3);100^(2*x-y) B: x<-log10(2);y<-log10(3);100^(2*x-y) C: x<-log10(2);y<-log10(3);100^(2x-y) D: x<-log(2);y<-log(3);100^(2x-y)

    • 1

      函数的定义域是( ) A: {(x,|2<x2+y2<3} B: {(x,|4<x2+y2<9} C: {(x,|4<x2+y2≤9} D: {(x,|22+y2≤3}

    • 2

      绘制函数 z=(x+y)^2 的曲面图 A: x=-3:0.1:3; y=-3:0.1:3; z=(x+y)^2; surf(x,y,z) B: x=-3:0.1:3; y=-3:0.1:3; z=(x+y).^2; surf(x,y,z) C: x=-3:0.1:3; y=-3:0.1:3; z=(x+y).^2; meshgrid(x,y,z); surf(x,y,z) D: x=-3:0.1:3; y=-3:0.1:3; [X,Y]=meshgrid(x,y); Z=(X+Y).^2; surf(X,Y,Z)

    • 3

      记函数y=log2(x+1)的反函数为y=g(x),则g(3)=(  ) A: 2 B: 3 C: 7 D: 8

    • 4

      设\(z = u{e^v}\),\(u = {x^2} + {y^2}\),\(v = xy\),则\( { { \partial z} \over {\partial x}}=\) A: \({e^{xy}}({x^2}y + {y^3} + 2x)\) B: \({e^{xy}}({x}y^2 + {y^3} + 2x)\) C: \({e^{xy}}({x}y + {y^3} + 2x)\) D: \({e^{xy}}({x^2}y + {y^2} + 2x)\)