%%HP: T(1)A(D)F(,);
«
"r1+r2=2a e=d(S;F) aa-"
1 DISP
" ee=bb xx/a^2+yy/b^2=1"
2 DISP
"S=‡ab yy=bb/a^2(aa-xx)"
3 DISP
"…=e/a=ƒ(1-b²/a²) x²b²+"
4 DISP
" a²y²=a²b² TE: xx1/a²+"
5 DISP " yy1/b²=1"
6 DISP
"H: x²b²-a²y²=a²b²"
7 DISP 3 FREEZE
»