Ce qu'il faut retenir :
Formules de conjugaison :
Origine au sommet | \(\frac{n_{1}}{\overline{SA_{1}}} - \frac{n_{2}}{\overline{SA_{2}}} = \frac{n_{1} - n_{2}}{\overline{SC}}\) \(\gamma = \frac{n_{1}}{n_{2}} \frac{\overline{SA_{2}}}{\overline{SA_{1}}}\) |
Origine au centre | \(\frac{n_{1}}{\overline{CA_{2}}} - \frac{n_{2}}{\overline{CA_{1}}} = \frac{n_{1} - n_{2}}{\overline{CS}}\) \(\gamma = \frac{\overline{A_{2}B_{2}}}{\overline{A_{1}B_{1}}} = \frac{\overline{CA_{2}}}{\overline{CA_{1}}}\) |
Origine aux foyers | \(\overline{FA_{1}} ~\overline{F'A_{2}} = \overline{SF}~ \overline{SF'} = f f'\) \(\gamma = - \frac{f}{\overline{FA_{1}}} = \frac{\overline{F'A_{2}}}{f'}\) |
Relation de Lagrange-Helmholtz:
\(n_{1}~ \overline{A_{1}B_{1}}~\theta_{1} = n_{2} ~\overline{A_{2}B_{2}}~ \theta_{2}\)