SOLUTION: Determine k such that the solutions of {{{9x^2 + 9x = k}}} are complex numbers.

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Question 867606: Determine k such that the solutions of 9x%5E2+%2B+9x+=+k are complex numbers.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Same as 9x%5E2%2B9x-k=0.
Wanting solutions complex, this is a discriminant problem exercise.
Discriminant is 9%5E2-4%2A9%2A%28-k%29.
9%5E2-4%2A9%2A%28-k%29%3C0
81%2B36k%3C0
36k%3C-81
k%3C-81%2F36
highlight%28k%3C-2%261%2F4%29