SOLUTION: For what value(s) of d does the function f(x)=dx^2-6x+d have no zeros? Thanks very much appreciated :)

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Question 1032935: For what value(s) of d does the function f(x)=dx^2-6x+d have no zeros?
Thanks very much appreciated :)
Found 2 solutions by robertb, josgarithmetic:
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
The discriminant b%5E2+-+4ac+=+36+-+4%2Ad%2Ad+=+36+-+4d%5E2+%3C+0.
Hence 36+%3C+4d%5E2, or 9+%3C+d%5E2.
==> Therefore d is any number in (-infinity, -3) ∪ (3, infinity).

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Discriminant would be negative for no real zeros.

%28-6%29%5E2-4%2Ad%2Ad%3C0