Jun 22, 2013  From:Original  Author:AP数学组




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).