Let M(m? , n) Ellipse x 2/a 2+? y^2/b^2= 1(a>; B>0), r 1 and r2 are point m and point f &;; #832 1; (-c,0),F & amp#8322; (c, 0), then (left focal radius) r &;; #832 1; =a+em, (right focal radius) r &;; #8322; =a? -em, where e is eccentricity.
Deduction: R &;; #832 1; /∣MN 1∣=? r & amp#8322; /∣MN2∣=e
Available: r 1=? e∣MN 1∣=? e(a^2/? c+m)=? a+em,r2=? e∣MN2∣=? e(a^2/? c-m)=? Hmm.
So: ∣MF 1∣=? a+em,∣MF2∣=? Hmm.
Honey, if you have time, you can have it yourself.