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**kingsolomonsgrave** $\displaystyle f(x)=(5x+sqrt(x^2+2x))/4+x$

I figure that the domain can't include -4 and $\displaystyle x^2+2 $ is greater than or equal to zero

working from there I get

$\displaystyle x^2+2x $, is greater than or equal to zero so

$\displaystyle x^2$ is greater than or equal to $\displaystyle -2x$

and therefore x is greater than or equal to -2

however I have been told the answer is actually x equal to or LESS than -2

I don't understand, where did x become less than -2?