• 2021-04-14
    【单选题】与曲线 y = x 2 相切,且与直线 x + 2 y + 1 = 0 垂直的直线的方程为 ()
    A. y = 2 x - 1 B. y = 2 x + 2 C. y = 2 x - 2 D. y = 2 x + 1
  • y = 2 x - 1

    举一反三

    内容

    • 0

      方程$(x^2+1)(y^2-1) + xy y' = 0$的通解为 A: $y^2 = C \frac{e^{-x^2}}{x^2}$ B: $y = C \frac{e^{-x^2}}{x^2}$ C: $y^2 = C \frac{e^{-x^2}}{x^2}+1$ D: $y=C \frac{e^{-x^2}}{x^2}+1$

    • 1

      直线经过点C(1,2),且垂直于y轴,直线方程为: A: x=1 B: y=2 C: x=2 D: y=1

    • 2

      【单选题】Python中执行赋值语句x, y, z = 1, 2, 3后,再执行z, x, y = y, z, x,变量x、y、z中分别赋值为____。 A. x=1, y=2, z=3 B. x=3, y=1, z=2 C. x=2, y=1, z=3 D. x=3, y=2, z=1

    • 3

      分段函数:[img=206x91]18037123bea18f3.png[/img],下面程序段中正确的是__________。 A: If x < 0 Then y = 0If x < 1 Then y = 1If x < 2 Then y = 2If x >= 2 Then y = 3 B: If x > =2 Then y = 3ElseIf x > =1 Then y = 2ElseIf x > =0 Then y = 1Else y = 0End If C: If x >= 2 Then y = 3If x >= 1 Then y = 2If x > 0 Then y = 1If x < 0 Then y = 0 D: If x < 0 Then y = 0ElseIf x > 0 Then y = 1ElseIf x > 1 Then y = 2Else y = 3End If E: If x < 0 Then y = 0If 0 <= x <1 Then y = 1If 1 <= x < 2 Then y = 2If x >= 2 Then y = 3

    • 4

      求方程$y\frac{{{d}^{2}}y}{d{{x}^{2}}}-(\frac{dy}{dx})^{2}=0$的通解: A: $y={{C}_{1}}{{e}^{-{{C}_{2}}x}}$ B: $y={{C}_{1}}{{e}^{-{{C}_{2}}{{x}^{2}}}}$ C: $y={{C}_{1}}x{{e}^{-{{C}_{2}}{{x}^{2}}}}$ D: $y={{C}_{1}}{{e}^{{{C}_{2}}x}}$