| Routh's Criterion |
| 1 |
3 |
2 |
-1 |
| 2 |
-1 |
-1 |
|
| 3.5 |
2.5 |
-1 |
0 |
| -2.42857142857143 |
-0.428571428571429 |
0 |
0 |
| 1.88235294117647 |
-1 |
0 |
0 |
| -1.71875 |
0 |
0 |
0 |
| -1 |
0 |
0 |
0 |
| 0 |
0 |
0 |
0 |
The polynomial p(x) = x6 + 2x5 + 3x4
- x3 + 2x2 - x - 1 has three roots
with positive real parts.
Reference: K. Ogata, Modern Control Engineering, pp. 253-257.