+118667 Like this
\(\lfloor 2x^2-x \rfloor=0\\ \text{It will be true when }\qquad 0\le2x^2-x <1\\~\\ Let\;\;y=2x^2-x\\ \text{It will be true when }\qquad 0\le y<1\\~\\ \)
y=2x^2-x \\
y=x(2x-1)
this is a concave up parabola with roots of x=0 and x=0.5
So between x=0 and x=0.5 the y value will be negtive so those points are no good.
Where does this parabola intersect with y=1?
\(y=1\\ 1=2x^2-x\\ 2x^2-x-1=0\\ \)
I solved using the quadratic equation
\(x=1 \;\;or\;\;-0.5\\~\\ \text{So the statement will be true for }\quad \\~\\ -0.5
