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Limit Computation
  
The following problem reviews some important skills from precalculus. So, let’s take a look:


Computation of this limit starts with analysis of a rational function, then uses the graph of the natural logarithmic function.

First, by Laws of Logarithms, we obtain


Now, as  x  approaches , we will first investigate where the blue goes.
Each of the three small fractions  3/x, 1/x2, and another 1/x2  will approach  0. And, since  x  approaches +, we also see that each of these small fractions remains positive. Symbolically, we could describe this analysis as:
Let
Then, when  x  approaches +, we see that  u  approaches  0+.
From the graph of  v = ln(u)  below, we know that  v  now approaches  . This is the answer.

As we see in the graph, as the input approaches  0+, the output of the  ln  function approaches  .

No support for LM Objects
 
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