[单选题]曲面z=1-x2-y2在点(1/2,1/2,1/2)处的切平面方程是: A x+y+z-3/2=0 B x-y-z+3/2=0 C x-y+z-3/2=0 D x-y+z+3/2=0 发布时间:2024-04-10 09:28:02