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Computation of Limits


Maxima can compute limits for a wide range of rational and transcendental functions.

For rational functions, it is often important to know the value at inifinity:

 limit ((x^2 - 1)/(x^2 + 1), x, inf);
     1

The value of a "0/0" expression can be easily computed:

 limit ((x^2 + x - 6)/(x^4 + x^3 - 19*x^2 + 11*x + 30), x, 2);
    5
  - --
    21

Occasionally a limit from the right side differs from the limit from the left side at the same point:

 limit (tan(x), x, %pi/2, plus);
  minf

This is the limit from the right side: It is taken for values %pi/2 + epsilon for increasingly small positive values of epsilon. Maxima finds the limit value minus inifinity.

When we take the limit at the same point from the left, we obtain:

 limit (tan(x), x, %pi/2, minus);
  inf

We can also try to compute that limit without telling Maxima fromwhich side we want to compute it:

 limit (tan(x), x, %pi/2);
  und

This answer means undefined. This is a hint that we should compute the limit from both sides.

Here is a different example:

 limit (tan(3*x)/tan(x), x, %pi/2);
   1
   -
   3


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