let x1>x2>x3>x4>x5>x6>0, and
A= x1+x2+.......+x6
B= x1x3+x3x5+x1x5+x2x4+x2x6+x4x6
C= x1x3x5+x2x4x6,
then the equation 2x^3 - Ax^2 + Bx - C = 0 has
1. exactly one real root
2. three positive roots
3. three negative roots
4. none of these
let x1>x2>x3>x4>x5>x6>0, and
A= x1+x2+.......+x6
B= x1x3+x3x5+x1x5+x2x4+x2x6+x4x6
C= x1x3x5+x2x4x6,
then the equation 2x^3 - Ax^2 + Bx - C = 0 has
1. exactly one real root
2. three positive roots
3. three negative roots
4. none of these