所以说球坐标系,其实就是在rz平面再建立一个极坐标。

So the idea of spherical coordinate is you're going to polar coordinates again in the rz plane.

youdao

球坐标中的平面也差不多是这样了，只要把rz看做极坐标就行了。

That's in line with the idea that we are just doing again, polar coordinates in the rz directions.

youdao

极坐标是关于r，θ的,用r，θ代替平面上一点的x，y坐标，是从原点到那一点的距离，，which，is，the，distance，from，the，origin，to，a，point，θ是由x轴逆时针旋转,而得到的夹角。

Remember that polar coordinates are about replacing x and y as coordinates for a point on a plane by instead r, r and theta,which is the angle measured counterclockwise from the positive x-axis.

youdao

Another way to represent a point in a plane is I've got a radius and I've got an angle from the x-axis, right, and that's a standard thing you might do.

平面上面的点的方法,也就是极坐标,上面那种方法其实是，如果你们喜欢我这么说的话,笛卡尔坐标表示法。

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