Kitani Minoru[?] (1909-1975) Great friend and rival to Go Seigen. Go and Kitani were the vanguard of the Shin-fuseki or "New Opening", a great advance in go theory
Sakata Eio[?] (born 1920) "Razor Sakata", the "Master of myoushu" (brilliant move) former longtime holder of most championship titles with 64.
Cho Hunhyun[?] (born 1953) (조훈현 ; 曺薰鉉) Perhaps the second strongest player in the world, after his former pupil Lee Changho.
Cho Chikun[?] (born 1956) (조치훈 ; 趙治勳 Cho Chihun[?] in Korean)Among the best players of the last century - passed Sakata in late 2002 for most titles with 66.
... significance for details.
Derivation
The quadratic formula is derived by the method of completing the square[?].
<math>ax^2+bx+c=0</math>
Dividing ...