Verovatno je
04sale82 želeo nešto ovako:
Tačka
![](https://static.elitesecurity.org/tex/1b13a5abf7238a3290b69d8d9fd96f80.png)
pripada krugu
![](https://static.elitesecurity.org/tex/840111e206dd918b0e29c8533bbf583e.png)
akko postoji
![](https://static.elitesecurity.org/tex/931a3050d3b20e03ead7c892500de65d.png)
tako da je
![](https://static.elitesecurity.org/tex/e291a8416c1a687b6d3ca2a7843523af.png)
i
![](https://static.elitesecurity.org/tex/c5c3a09157e02be113049e5f0f5603d1.png)
.
Jedan smer je posledica osnovnog trigonometrijskog identita, a drugi se dokazuje pravolinijski, razlikovanjem slučajeva i upotrebom f-je
![](https://static.elitesecurity.org/tex/95312bbfa94962ed1c184711178f8439.png)
.
Znači, ako tačka
![](https://static.elitesecurity.org/tex/1b13a5abf7238a3290b69d8d9fd96f80.png)
pripada elipsi
![](https://static.elitesecurity.org/tex/e16ca8b5cce2d4dca0cfa746afa2a66b.png)
, onda tačka
![](https://static.elitesecurity.org/tex/939944aab26b2e95b741e7c388cc6d3a.png)
pripada krugu
![](https://static.elitesecurity.org/tex/aa15306fbd0d12e277e062fe9c1e093e.png)
, pa postoji
![](https://static.elitesecurity.org/tex/931a3050d3b20e03ead7c892500de65d.png)
za koje važi
![](https://static.elitesecurity.org/tex/183bfb439b7a3b6a678ee7e68ff400cf.png)
i
![](https://static.elitesecurity.org/tex/abd6c584d44c19ab697001920475a898.png)
, a to je upravo ono što smo i hteli.
![](https://www.elitesecurity.org/images/static/emoticons/smile.gif)
Attempt all the problems. Those you can do, don't do. Do the ones you cannot.