求f(x,y,z)=xsin（yz）在点(1,3,0)处沿方向L=(1,2,-1)的方向导向等于_______
举一反三
- 求f(x,y)=xy+sin(x+2y)在点(0,0)沿方向L＝(1,2)的方向导数等于________
- 函数\( u = 2xy - {z^2} \)在点\( (1, - 1,1) \)处沿\( \overrightarrow l = (1,2, - 2) \)方向的方向导数是 ______
- 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
- 调用下面函数,错误的是( )。def f(x, y = 0, z = 0): pass #空语句,定义空函数体 A: f(z = 3, x = 1, y = 2) B: f(1, x = 1, z = 3) C: f(1, y = 2, z = 3) D: f(1, z = 3)
- 执行下面代码，错误的是def f(x, y = 0, z = 0): pass # 空语句，定义空函数体 A: f(1, x = 1, z = 3) B: f(z = 3, x = 1, y = 2) C: f(1, z = 3) D: f(1, y = 2, z = 3)