设函数<img src="https://zk.995w.com/lqwvjeImg/5f/5fe03a1e0cddcbdcb2df8945c20035d5.png" style="font-size: 14px;" >在点(0,0)的某邻域内有定义,且<img src="https://zk.995w.com/lqwvjeImg/ef/ef79dfe11d7cedcc75c532efdb683693.png" style="font-size: 14px;" >,<img src="https://zk.995w.com/lqwvjeImg/34/34efaf8a6e4befd73d44c8099c120de0.png" style="font-size: 14px;" >,则有( )<br>·<img src="https://zk.995w.com/lqwvjeImg/f4/f450c7446fb024ee78cfc210fbe19833.png" ><br>·曲面<img src="https://zk.995w.com/lqwvjeImg/05/05c4ef15170695e10b939fcaae6ca571.png" 在点<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1654591582366_0fa232711e23404489e66286f811bbc1.png" 的一个法向量为(3,-1,1)<br>·曲面<img src="https://zk.995w.com/lqwvjeImg/44/447174d8dab92c7a42ee3f1494a2a2e0.png" 在点<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1654591599067_97c4edec3543482f973b58bb49cb1f2a.png" >的一个切向量为(1,0,3)<br>·曲面<img src="https://zk.995w.com/lqwvjeImg/27/273b1285ff44b21d256745f0b31ecdb8.png" 在点<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1654591602024_b767e74a17314699b5d5226d8ae7b33e.png" >的一个切向量为(3,0,1)