domingo, 4 de noviembre de 2012


PF2+PF1=2A
PF2=(x-(x-c))2 + (y-0)2
PF1=(x-c)2 + (y-0)2
(x-c)2 + y2 + (x+c)2 + y2 = 2A
(x+c)2 + y2 = 2a - (x-c)2 + y2
 (x+c)2 + y2  = 4a2-4a(x-c)2 + y2 + (x-c)2 + y2
X2 + 2xc + c2 = 4a2 – 4a(x-c)2 + y2 + x2 – 2xc + c2
4xc = 4a2- 4ª (x-c)2 + y2
Xc= a2 – a (x-c)2 + y2
Xc – c2 = -a(x-c)2 + y2
-Xc + a2 = +a(x-c)2 + y2
(a2 – Xc )/ a = (x-c)2 + y2
a -(Xc / a ) = (x-c)2 + y2
(a-[Xc/a])2 = (x-c)2 + y2
a2 – 2xc  + (x2c2/a2)= x2 -2xc +c2 + y2
x2 – (c2/a2)x2 – a2 +c2 + y2= 0
(a2-c2/a2)x2 + c2 – a2 +y2= 0
(b2/a2)x2 –b2 + y2=0
(b2/a2)x2 + y2 = b2
(b2x2 + a2y2)/a2 = a2b2/a2
 b2x2 + a2y2 = a2b2
([b2x2+a2]/a2b2)y2 = a2b2/a2b2
(x2/a2)+(y2/b2)=1

Carlos Jacobo Morales Molina









                                                       

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