⑩天掌 Teaching Plan on Advanced Mathematics o 旋转过程中的特征: 设M(x,y,z), (1)z (2)点M到z轴的距离 d=、x2+y V1 将z=1,y1=土√x2+y2代入 f(y1,z1)=0 tianjin polytechnic dmivendityTianjin Polytechnic University Teaching Plan on Advanced Mathematics 1 (1) z = z （2）点M 到 z轴的距离 | | 1 2 2 d = x + y = y 旋转过程中的特征： 将 代入 2 2 1 1 z = z , y =  x + y ( , ) 0 f y1 z1 = 设 M(x, y,z)