SOLUTION: Find the values of k such that x² + 6x + k = 0 will have exactly two solutions. x² + 6x + k = 0

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Question 1179527: Find the values of k such that x² + 6x + k = 0 will have exactly two solutions.
x² + 6x + k = 0
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!

x%5E2+%2B+6x+%2B+k+=+0

function will have exactly two solutions if discriminant b%5E2-4ac%3E0
in your case a=1, b=6, and c=k
6%5E2-4%2A1%2Ak%3E0
36-4k%3E0
36%3E4k
36%2F4%3Ek
k%3C9

solution interval:
(-infinity,9)

let k=8
x%5E2+%2B+6x+%2B+8+=+0
%28x+%2B+2%29+%28x+%2B+4%29+=+0
solutions:
x=-2 and x=-4

+graph%28600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+x%5E2+%2B+6x+%2B+8+%29+