# Math Help - Supremum

1. ## Supremum

$Sup {x \in \Re: x^2+4x+1<0}$

I'm not sure how to get the set brackets up so here it is without the math bits next to it:

Sup {x \in \Re: x^2+4x+1<0}

2. Did you graph $x^2 +4x +1$?
3. Well I can use the quadratic formula to get $\frac{-4 + \sqrt {4^2-4}}{{2}}=\frac{-4 + \sqrt{12}}{2}=\frac{-4 + 2 \sqrt 2}{2}=-2+\sqrt 2$.
I was just thinking that the answer would be zero since the greatest value of $x^2+4x+1$ is 0. I can see what I was doing wrong now.