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Question Number 39955 by rahul 19 last updated on 13/Jul/18

Commented by tanmay.chaudhury50@gmail.com last updated on 14/Jul/18

Commented by tanmay.chaudhury50@gmail.com last updated on 14/Jul/18

Answered by tanmay.chaudhury50@gmail.com last updated on 14/Jul/18

for hyperbola  (x^2 /A^2 )−(y^2 /B^2 )=1   B^2 =A^2 (e_2 ^2 −1)  for ellipse  b^2 =a^2 (1−e_1 ^2 )  foci of hyerbola =(Ae_2 ,0)and(−Ae_2 ,0)  vertices of ellipse =(a,0) and(−a,0)  foci of ellipse(ae_1 ,0) and(−ae_1 ,0)  given ae_1 =A    so (a/A)=(1/e_1 )  Ae_2 =a    (a/A)=e_2     (1/e_1 )=e_2   ((b/B))^2 =((a^2 (1−e_1 ^2 ))/(A^2 (e_2 ^2 −1)))=((e_2 ^2 (1−(1/e_2 ^2 )))/((e_2 ^2 −1)))=1

$${for}\:{hyperbola}\:\:\frac{{x}^{\mathrm{2}} }{{A}^{\mathrm{2}} }−\frac{{y}^{\mathrm{2}} }{{B}^{\mathrm{2}} }=\mathrm{1}\:\:\:{B}^{\mathrm{2}} ={A}^{\mathrm{2}} \left({e}_{\mathrm{2}} ^{\mathrm{2}} −\mathrm{1}\right) \\ $$$${for}\:{ellipse}\:\:{b}^{\mathrm{2}} ={a}^{\mathrm{2}} \left(\mathrm{1}−{e}_{\mathrm{1}} ^{\mathrm{2}} \right) \\ $$$${foci}\:{of}\:{hyerbola}\:=\left({Ae}_{\mathrm{2}} ,\mathrm{0}\right){and}\left(−{Ae}_{\mathrm{2}} ,\mathrm{0}\right) \\ $$$${vertices}\:{of}\:{ellipse}\:=\left({a},\mathrm{0}\right)\:{and}\left(−{a},\mathrm{0}\right) \\ $$$${foci}\:{of}\:{ellipse}\left({ae}_{\mathrm{1}} ,\mathrm{0}\right)\:{and}\left(−{ae}_{\mathrm{1}} ,\mathrm{0}\right) \\ $$$${given}\:{ae}_{\mathrm{1}} ={A}\:\:\:\:{so}\:\frac{{a}}{{A}}=\frac{\mathrm{1}}{{e}_{\mathrm{1}} } \\ $$$${Ae}_{\mathrm{2}} ={a}\:\:\:\:\frac{{a}}{{A}}={e}_{\mathrm{2}} \:\: \\ $$$$\frac{\mathrm{1}}{{e}_{\mathrm{1}} }={e}_{\mathrm{2}} \\ $$$$\left(\frac{{b}}{{B}}\right)^{\mathrm{2}} =\frac{{a}^{\mathrm{2}} \left(\mathrm{1}−{e}_{\mathrm{1}} ^{\mathrm{2}} \right)}{{A}^{\mathrm{2}} \left({e}_{\mathrm{2}} ^{\mathrm{2}} −\mathrm{1}\right)}=\frac{{e}_{\mathrm{2}} ^{\mathrm{2}} \left(\mathrm{1}−\frac{\mathrm{1}}{{e}_{\mathrm{2}} ^{\mathrm{2}} }\right)}{\left({e}_{\mathrm{2}} ^{\mathrm{2}} −\mathrm{1}\right)}=\mathrm{1} \\ $$$$ \\ $$

Commented by tanmay.chaudhury50@gmail.com last updated on 14/Jul/18

e_1 +e_2 =((√e_1 ) −(√e_2 ) )^2 +2(√(e_1 e_2 ))     =((√e_1 ) −(√e_2 ) )^2 +2  (since e_1 e_2 =1 already proved)  e_1 +e_2 >2  so e_1 +e_2   can not be equals to 2

$${e}_{\mathrm{1}} +{e}_{\mathrm{2}} =\left(\sqrt{{e}_{\mathrm{1}} }\:−\sqrt{{e}_{\mathrm{2}} }\:\right)^{\mathrm{2}} +\mathrm{2}\sqrt{{e}_{\mathrm{1}} {e}_{\mathrm{2}} } \\ $$$$\:\:\:=\left(\sqrt{{e}_{\mathrm{1}} }\:−\sqrt{{e}_{\mathrm{2}} }\:\right)^{\mathrm{2}} +\mathrm{2}\:\:\left({since}\:{e}_{\mathrm{1}} {e}_{\mathrm{2}} =\mathrm{1}\:{already}\:{proved}\right) \\ $$$${e}_{\mathrm{1}} +{e}_{\mathrm{2}} >\mathrm{2}\:\:{so}\:{e}_{\mathrm{1}} +{e}_{\mathrm{2}} \:\:{can}\:{not}\:{be}\:{equals}\:{to}\:\mathrm{2} \\ $$

Commented by rahul 19 last updated on 15/Jul/18

Thank You Sir ! ������

Commented by tanmay.chaudhury50@gmail.com last updated on 15/Jul/18

its ok...at the age of 48 still interested in  physics and math...look back...the year 1988.  when i was in class XII..

$${its}\:{ok}...{at}\:{the}\:{age}\:{of}\:\mathrm{48}\:{still}\:{interested}\:{in} \\ $$$${physics}\:{and}\:{math}...{look}\:{back}...{the}\:{year}\:\mathrm{1988}. \\ $$$${when}\:{i}\:{was}\:{in}\:{class}\:{XII}.. \\ $$

Commented by rahul 19 last updated on 15/Jul/18

That's the spirit! ������������

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