Question 1032935
The discriminant {{{b^2 - 4ac = 36 - 4*d*d = 36 - 4d^2 < 0}}}.

Hence {{{36 < 4d^2}}}, or {{{9 < d^2}}}.

==> Therefore d is any number in ({{{-infinity}}}, -3) &#8746; (3, {{{infinity}}}).