F(x) [F(x)^2-1] =0
F(x)=O or F(x) =+1,-1
Also it has to be discontinuous at x=o
So from -infy to zero , at 0 , from 0 to infy .
Fx will take value 0,1,-1
So make combinations
@Kirito why we are making combination ?
Like this graphs of fx are possible