SOLUTION: Find the values of K such that the equation 3x^2 + 10x + K =0 has imaginary roots. I came up with a answer of 25/3 but wasnt sure if that was right

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Question 304980: Find the values of K such that the equation 3x^2 + 10x + K =0 has imaginary roots.
I came up with a answer of 25/3 but wasnt sure if that was right

Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!

You said you thought the answer is 25%2F3.  NO!  There are infinitely
many answers, not just one.  Notice the word "valueS", with an "S", 
not "value". So your answer must be incorrect.  You must
answer with an inequality or with a set in interval notation. 

3x%5E2+%2B+10x+%2B+K+=0

DISCRIMINANT+=+B%5E2+-+4AC+=+10%5E2-4%283%29%28K%29+=+100-12K

For the roots to be imaginary this must be negative, which
is the same as less than zero, so we set 100-12K less
than zero.

100-12K%3C0
-12K%3C-100
%28-12K%29%2F%28-12%29+%3E%28-100%29%2F%28-12%29
K+%3E+25%2F3 [Note that the inequality reversed because we divided by a negative number] 

The answer is the set of real numbers GREATER THAN 25%2F3.
So 25%2F3 is not even an answer at all, since 25%2F3 is
not greater than itself!!!!

The answer is that K is in the interval %22%5B%2225%2F3%22%2C%22infinity%22%29%22  

Edwin