The given quadratic equation is x2−ax+2=0 with roots e1 and e2.
The sum of the roots is e1+e2=a and the product is e1e2=2.
For the roots to be real and distinct, the discriminant must be positive:
Δ=a2−8>0⇒a∈(−∞,−22)∪(22,∞)
Since e1 and e2 represent eccentricities, they must be positive. Given e1e2=2>0, both roots have the same sign. For them to be positive, their sum must be positive, so a>0. Thus, a>22.
For e1 and e2 to be the eccentricities of hyperbolas, both must be strictly greater than 1. This requires 1 to lie outside the roots and the vertex of the parabola to be to the right of 1:
(e1−1)(e2−1)>0⇒e1e2−(e1+e2)+1>0
2−a+1>0⇒a<3
Combining this with the discriminant condition, we get a∈(22,3).
Thus, α=22 and β=3.
For e1 and e2 to be the eccentricities of an ellipse and a hyperbola, one root must be in (0,1) and the other in (1,∞). This requires 1 to lie between the roots:
(e1−1)(e2−1)<0⇒2−a+1<0⇒a>3
For a>3, the roots are real, distinct, and positive. Thus, the set of such a is (3,∞).
This gives γ=3.
Finally, calculating the required sum:
α2+β2+γ2=(22)2+32+32=8+9+9=26
Answer: 26