• 2021-04-14
    1.What is the right account of "Perez y Martina"?
  • B

    内容

    • 0

      设\(z = xy{e^{\sin xy}}\),则\({z'_y} = \)( )。 A: \(x{e^{\sin xy}}\left( {1 + xy\cos xy} \right)\) B: \(y{e^{\sin xy}}\left( {1 + xy\cos xy} \right)\) C: \(x{e^{\sin xy}}\left( {1 + y\cos xy} \right)\) D: \(x{e^{\sin xy}}\left( {1 - xy\cos xy} \right)\)

    • 1

      求函数$y = \arccos (4x)$的定义域( )。 A: $\left[ { - {1 \over 4},{1 \over 4}} \right]$ B: $\left[ { - 1,1} \right]$ C: $\left[ {0,1} \right]$ D: $\left[ { - 4,4} \right]$

    • 2

      设\(f\left( {x,y,z} \right) = x{y^2} + y{z^2} + z{x^2}\),则\({f_{yz}}\left( {0,-1,0} \right) = \)( ) A: 1 B: 0 C: -1 D: 2

    • 3

      The account title of a T account appear above the T. Debit entries are depicted to the right of the "T" and credits are shown to the left of the "T".

    • 4

      函数$z=\arcsin\dfrac{1}{~\sqrt{x+y}~}$的定义域为( ) A: $\left\{(x,y)\left|~x+y\geq<br/>0\right.\right\}$; B: $\left\{(x,y)\left|~x+y\geq<br/>1~\text{或}~x+y\leq<br/>-1 \right.\right\}$; C: $\left\{(x,y)\left|~x+y\geq<br/>1\right.\right\}$; D: $\left\{(x,y)\left|~x+y\geq<br/>\dfrac{4}{~\pi^2~}\right.\right\}$.