|cosx|≤1
lim(x->∞) e^(-x^2) .cosx
=0������ϸ����|cosx|��10��e^(-x^2) . cosx �� e^(-x^2)0��lim(x->��)e^(-x^2) . cosx �� lim(x->��)e^(-x^2)0��lim(x->��)e^(-x^2) . cosx ��0=>lim(x->��) e^(-x^2) . cosx =0