If `e_(1)` and `e_(2)` are the eccentricities of two conics with `e_(1)^(2) + e_(2)^(2) = 3` , then the conics are

If e and e' be the eccentricities of two conics S=0 and S'=0 and if e^(2)+e'^ (2)=3 , then both S and S' can be

If e_(1) and e_(2) are the eccentricities of a hyperbola 3x^(2)-2y^(2)=25 and its conjugate, then

If e and e_(1) are the eccentricities of xy=c^(2),x^(2)-y^(2)=a^(2) then e^(4)+e_(1)^(4)=

If e_(1) and e_(2) are the eccentricities of the hyperbolas xy=9 and x^(2)-y^(2)=25 then (e_(1),e_(2)) lie on a circle c_(1) with centre origin then (radius )^(2) of the director circle of c_(1) is

If e_(1) and e_(2) are respectively the eccentricities of the ellipse (x^(2))/(18)+(y^(2))/(4)=1 and the hyperbola (x^(2))/(9)-(y^(2))/(4)=1 , then the relation between e_(1) and e_(2) , is

If e_(1) and e_(2) are the eccentricities of the ellipse (x^(2))/(18)+(y^(2))/(4)=1 and the hyperbola (x^(2))/(9)-(y^(2))/(4)=1 respectively and (e_(1), e_(2)) is a point on the ellipse 15x^(2)+3y^(2)=k , then the value of k is equal to