y=(arctanx/x)^(1/x^2)lny=(1/x^2)ln(arctanx /x) =ln(arctanx/x)/ x^2 x->0 arctanx/x->1 ln(arctanx/x) ->0, x^2->0 lim(x->0)lny =lim(x->0) [ln(arctanx /x) ]' / (x^2)'=(x/arctanx)*[1/(1+x^2)*x -arctanx/x^2] /2x
