f=@(x)((x-0.1428)./(0.2539-0.1428)).*(x>=0.1428&x<=0.2539)+((0.3490-x)./(0.3490-0.2539)).*(x>0.2539&x<=0.3490);
g=@(x)integral(f,0,x)-integral(f,x,0.3490);
x=fzero(g,0.2)
x =
0.2498