Vietove formulice
Kvadratne funkcije
<p>Prepišite tablicu u bilježnicu. Riješite jednadžbe, dovršite tablicu. Promatrajte i usporedite unose u stupcima. Što primjećujete?</p>
<table class=' table table-bordered table-striped'>
<tr>
<td>Jednadžba</td>
<td>b</td>
<td>c</td>
<td>x<sub>1</sub></td>
<td>x<sub>2</sub></td>
<td>x<sub>1</sub> + x<sub>2</sub></td>
<td>x<sub>1</sub> · x<sub>2</sub></td>
</tr>
<tr>
<td>x<sup>2</sup> + §§V0(2,10,1)§§x + §§V1(3,17,2)§§ = 0</td>
<td>+§§V0(2,10,1)§§ </td>
<td>+§§V1(3,17,2)§§</td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td>x<sup>2</sup> + §§V2(2,15,2)§§x - §§V3(12,30,1)§§ = 0</td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
<tr>
<td>x<sup>2</sup> - §§V4(2,10,1)§§x + §§V5(2,15,1)§§ = 0</td>
<td></td>
<td></td>
<td></td>
<td></td>
<td>
<img src="https://www.mathkiss.com/uploads/zec2.jpg" width="200"/>
</td>
<td></td>
</tr>
<tr>
<td>x<sup>2</sup> - §§V6(2,10,1)§§x - §§V7(20,30,1)§§= 0</td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr>
</table>
<p>Vieta je svoje spoznaje formulirao u rečenici koja se naziva „Vietin poučak“: Za rješenja x<sub>1</sub> i x<sub>2</sub> kvadratne jednadžbe x<sup>2</sup> + bx + c = 0 vrijedi: x<sub>1</sub> + x<sub>2</sub> = -b i x<sub>1</sub> · x<sub>2</sub> = c.</p>