Cases |
|
|
|
|
| No. of sign change | No. of positive real roots |
1 | + | + | + | + |
| 0 | 0 |
1 | + | + | + | − |
| 1 | 1 |
2 | + | + | − | + |
| 2 | 0, 2 |
2 | + | + | − | − |
| 1 | 1 |
3 | + | − | − | + |
| 2 | 0, 2 |
3 | + | − | − | − |
| 1 | 1 |
4 | + | − | + | + |
| 2 | 0, 2 |
4 | + | − | + | − |
| 3 | 1, 3 |