यदि वक्र ax2 + by2 = 1 और cx2 + dy2 = 1 एक दूसरे को लंबवत काटते हैं तब
1
\(\frac{1}{a} + \frac{1}{b} = \frac{1}{c} – \frac{1}{d}\)
2
\(\frac{1}{a} – \frac{1}{b} = \frac{1}{c} + \frac{1}{d}\)
3
\(\frac{1}{a} + \frac{1}{b} = \frac{1}{c} + \frac{1}{d}\)
4
\(\frac{1}{a} – \frac{1}{b} = \frac{1}{c} – \frac{1}{d}\)