/sci/ - Science & Math

this is all i have (x^2)+x-1<0
x=[1+sqrt(5)]/2 and [1-sqrt(5)]/2
the the sup is obviously the first x i wrote.
i let s=1+sqrt(5)]/2}
then i say there is an x in set A, where x<s or x=s, for all x in set A.

A={x : x^2 < 1 - x}
={x : (x + 1/2)^2 < 5/4}
={x : |x + 1/2| < sqrt(5)/2}
={x : (-1 + sqrt(5))/2 < x < (1 + sqrt(5))/2}

problem 4 you say?
>proof