1) F1=(c,0) , F2=(−c,0)
c2=a2−b2
c=√a2−b2
2) S=(xs,ys)∊ elipsy − punkt styczności
S'=(−xs,−ys}
| x2 | y2 | ||
+ | =1 równanie elipsy | ||
| a2 | b2 |
| x*xs | y*ys | |||
s1: | + | =1⇔ | ||
| a2 | b2 |
| xs | ys | ||
x + | *y−1=0 | ||
| a2 | b2 |
| −x*xs | −y*ys | |||
s2: | + | =1⇔ | ||
| a2 | b2 |
| −xs | −ys | ||
x + | *y−1=0 | ||
| a2 | b2 |
| x2 | y2 | |||
Na rysunku jest elipsa o równaniu: | + | =1 | ||
| 9 | 4 |