函数[img=197x27]18031be69f14e3a.png[/img]在点[img=74x28]18031be6a733a04.png[/img]处的梯度为（ ）。
A: [img=28x51]18031be6b070cac.png[/img]
B: [img=28x51]18031be6b8ea8b5.png[/img]
C: [img=28x51]18031be6c1729e8.png[/img]
D: [img=28x51]18031be6c9ab13d.png[/img]
A: [img=28x51]18031be6b070cac.png[/img]
B: [img=28x51]18031be6b8ea8b5.png[/img]
C: [img=28x51]18031be6c1729e8.png[/img]
D: [img=28x51]18031be6c9ab13d.png[/img]
举一反三
- 向量[img=28x51]180326371ad1eb1.png[/img]在基[img=98x51]1803263723d3478.png[/img]下的坐标向量为( ) A: [img=28x51]180326372b84c93.png[/img] B: [img=28x51]1803263733ca0ca.png[/img] C: [img=28x51]180326373c40786.png[/img] D: [img=28x51]1803263744697d0.png[/img]
- 1803b6a65bf4114.pngis a basis for a vector space V. [s[img=81x51]1803b6a6653a4f6.png[/img]. Which one is the vector x? A: [img=42x51]1803b6a66d43e0e.png[/img] B: [img=28x51]1803b6a6750b972.png[/img] C: [img=28x51]1803b6a67d4b84f.png[/img] D: [img=42x51]1803b6a685bca75.png[/img]
- 设[img=203x63]1803aff9db6bdc3.gif[/img]，则[img=103x46]1803aff9e39a89a.gif[/img]( ). A: [img=28x51]1803aff9eb85cc5.gif[/img] B: [img=28x51]1803aff9f3da699.gif[/img] C: [img=28x51]1803aff9fbe002e.gif[/img] D: [img=28x51]1803affa04b8466.gif[/img]
- 二元函数[img=271x27]18031be6d40080b.png[/img]的极值为（ ）。 A: 0 B: 1 C: [img=28x51]18031be6dcd79c5.png[/img] D: [img=28x51]18031be6e595a2e.png[/img]
- 设随机变量X,Y相互独立,且[img=167x27]17da6334a00d255.png[/img],[img=85x19]17da6334b1f3f8e.png[/img],则[img=55x27]17da6334bb9ebfa.png[/img]( ). A: 8 B: 16 C: 28 D: 44