We could do it dy dx. Or, maybe we will want to actually make a change of variables to first shift this to the origin, x-2 you know, change x to x minus two and then switch to polar coordinates.
也可以dy，dx来划分，或者,对变量做一下变化，移动到原点，就是把x变成,然后再转化成极坐标。
2
There are variables mankind does not normally consider that will be affecting life after the shift, such that an assumed plant or animal life would falter and simply die off, and others flourish.