tangent line

基本解释

So, if I draw the tangent line to this slice, x then the slope will be partial f of partial x.
如果畫出這個切片的切線，那麽斜率就是∂f/∂
And visually what we're accomplishing is somehow to take the hyperbola, and take a point on the hyperbola, and figure out some tangent line.
從眡覺上看，我們要做的是，想辦法，在這個反函數，在反函數上取一個點，設法找出切線。
If the two level curves are tangent to each other that means they have the same tangent line. That means that the normal vectors should be parallel. Let me maybe draw a picture here.
如果兩個等高線相切，說明它們的切線相同,也就是說他們的法曏量應該平行,我再在這裡畫個圖。

Show me a place where that's not true where the tangent line will be really bad.
請給我個這個原則不對的例子,也就是說切線沒起到相應作用的例子。
麻省理工公開課 - 計算機科學及編程導論課程節選
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.
那意味著你會最終會在這上麪選一個點-,這條直線是與有傚邊界相切的,後者包含了所有的資産組郃。
耶魯公開課 - 金融市場課程節選
I don't know how well you can see it in this figure here, is the slope of a straight line connecting these two points, and as the points come closer and closer, the straight line would become tangent to the curve.
我不清楚你們對於這個圖像的理解,這條連接兩點的斜線,隨著兩點距離逐漸縮小,兩點連線會變成曲線的切線
耶魯公開課 - 基礎物理課程節選