And, to go from one to the other, x+2y+4z Q1 If you're moving along any path from Q0 to Q1, 3 this thing will change continuously from 11 to 3.

,如果你从Q0沿任意一条路径移动到，值将连续地由11变到。

youdao

So, let's say that we take still the same line up there, x+2y+4z=7 and let's consider the plane with the equation x+2y+4z = 7.

我们还是看之前的那条直线，同时考虑平面。

youdao