我们要知道，它们之间的关系是什么,把dA设为xy坐标系的面积元素，dA就是，取决于顺序也许就要写成。

So, we want to understand, what's the relation between, let's call dA the area element dxdy in xy coordinates. So, dA is dxdy, dydx maybe dydx depending on the order.

youdao

然后，在uv坐标系内，把面积元素定义为dA，只是为了让他们看起来不同。

And, the area element in uv coordinates, let me call that dA prime just to make it look different.

youdao

所以这告诉我们dA，即uv坐标系中的面积元素，将比在xy坐标系内的，面积元素大了5倍。

So, that tells us that dA prime, the area element in uv coordinate is worth five times more than the area element in the xy coordinate.

youdao