So the velocity at any part of the curve is tangent to the curve at that point.

曲线上任意一点的速度,都在该点和曲线相切

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That means that you want to pick, ultimately, a point on this-- this line is tangent to the efficient portfolio frontier with all the other assets in it.

那意味着你会最终会在这上面选一个点-,这条直线是与有效边界相切的,后者包含了所有的资产组合。

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