什么是极限？
什么是极限？
为了理解微积分，你需要知道“极限”是什么。极限是函数的一个值（在AP考试中，函数经常记为f(x)），处理得到这个值，是在函数自变量（记为“x”）不断接近一个特定的值。也就是说，当x非常趋近一定值的时候，f(x)趋近什么值？至于AP微积分AB测试关注的是，你是否懂得计算极限。更多有关极限的计算方法，学生可以在AP微积分BC学习，但是我们这里不谈论，直到本章结束。
让我们看一个极限的例子：当x趋近2时，函数f(x)=x2的极限是什么？关于极限的符号，“当x趋近于2，f(x)的极限”写成
，为了计算极限，让我们对一些值进行检验，当x递增并且不断接近于2（没有真正达到2）。
what is a limit?
In order to understand calculus,you need to know what a "limit"is.A limit is the value a function(which usually is written"f(x)" on the AP exam) approaches as the variable within that function(usually "x")gets nearer and nearer to a particular value.In other words,when x is very close to a certain number,what is f(x) very close to? As far as the AB test is concerned, that's all you have to know about eva luating limits. There's a more technical method that you BC students have to learn, but we won't discuss it until we have to--at the end of this chapter.
Let's look at an example of a limit: What is the limit of the function f(x)=x2 as x approaches 2 ? In limit notation, the expression "the limit of f(x) as x approaches 2" is written like this:.In order to eva luate the limit,let's check out some values of as x increases and gets closer to 2 (without ever exactly getting there).
