11.7.1 Roots and poles of a rational function
The froot command finds roots and
poles of a rational function.
Examples
froot((x^5-2*x^4+x^3)/(x-2)) |
Hence, for F(x)=x5−2x4+x3/x−2:
-
1 is a root of multiplicity 2,
- 0 is a root of multiplicity 3,
- 2 is a pole of order 1.
froot((x^3-2*x^2+1)/(x-2)) |
|
| ⎡
⎢
⎢
⎣ | 1,1, | | ,1, | | ,1,2,−1 | ⎤
⎥
⎥
⎦ |
| | | | | | | | | | |
|
Remark.
To find the complex roots and poles, put Xcas in complex mode
(check the complex box in the CAS configuration, red button
giving the state line; see Section 2.5.5).
Example
Input in complex mode: