Square root of 16, and my plot basically shows it crosses at 4 and-- well, I think that's minus 4.

我的图清楚的显示这个函数,在4和-4两个点和x轴交合。

麻省理工公开课 - 计算机科学及编程导论课程节选

Yeah. Suppose I choose it right down there I guess 0. Well, the tangent there will not even have an x intercept. So I'm really going to be dead in the water.

好，如果我选猜想数为0，好吧,这个点的切线甚至和x轴都没交点,所以在这儿这一原则,真的不起作用了。

麻省理工公开课 - 计算机科学及编程导论课程节选

That's a choice, and that choice turns out to be very interesting and really important, because if you connect these two points together, you get a straight line that has to intercept the x-axis at some point.

在这一选择下,我们会发现一件非常有趣，而且极其重要的事,当你把这两点用直线连接起来，你会发现这条直线,将与x轴在某点相交。

麻省理工公开课 - 热力学与动力学课程节选

Let's create a graph here that on the x axis it's going to be time, so time zero will be when you first take in a food and then one hour later, two hours later will be shown as you go from left to right, and then we'll have blood glucose level up on the y axis.

我们在这建立一个曲线图,X轴代表的是时间,所以零时间点是你第一次进食的时间,然后一小时以后,两小时以后,是从左到右呈现在图表上的,在Y轴上是你的血糖值

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选