x | 1 | 2 | 3 | 4 |
y | ﹣3 | ﹣1 | 3 | 9 |
x | 0 | 0.5 | 1 | 1.5 | 2 |
y=ax2+bx+c | ﹣1 | ﹣0.5 | 1 | 3.5 | 7 |
| 1.6 | 1.8 | 2.0 | 2.2 | 2.4 |
| -0.80 | -0.54 | -0.20 | 0.22 | 0.72 |
x | 0 | 0.5 | 1 | 1.5 | 2 |
y=ax2+bx+c | -1 | -0.5 | 1 | 3.5 | 7 |
证明:.
售价x |
60 |
62 |
64 |
销售量y |
500 |
480 |
460 |