点
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/d043ad4bd11373f06c1ea12ba10f4bfbfbed0465?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
a
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/3801213fb80e7bec2bf5cd552a2eb9389b506b53?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
(3,3,0) 点b(3,0,0) c(3,0,3) d(3,3,3) e(3,3,0)
f(0,3,3) g(0,0,3)
函数x+y+z=4 常用点 (1,0,3) (2,0,2)等等 在图像标出即可。
![](https://video.ask-data.xyz/img.php?b=https://iknow-pic.cdn.bcebos.com/0824ab18972bd407d4931d497e899e510fb3092a?x-bce-process=image%2Fresize%2Cm_lfit%2Cw_600%2Ch_800%2Climit_1%2Fquality%2Cq_85%2Fformat%2Cf_auto)
平面ABC为 x+y+z=4
的方程图像。过程略。
当z=0时,图像为直线x+y=4
当x=0时,图像为直线z+y=4
当y=0时,图像为直线x+z=4
三条直线确立一个空间平面。
所有点也在这个平面上,通过全等,相似验证可得。
当z=0时为图像x+y=4
当z=1时为图像x+y=3
当z=2时为图像x+Y=2
随着z的增加,x+y=n不断向下移动,角度45度的平面