f(x):=log(x)^2;

p(x):=x^0.2;

wxplot2d([f(x),p(x)], [x,0,5],[y,-1,10]);

a:4000000000000000.0;p(a);f(a);

find_root(p(x)=f(x),x,3*10^15,4*10^15);

limit(f(x)/p(x),x,inf);