lim((sinx-ln(1+x^2)^1/2)/x^4) x->0求解 呵呵~sin改成-cosx+1

问题描述:

lim((sinx-ln(1+x^2)^1/2)/x^4) x->0求解 呵呵~
sin改成-cosx+1

呵呵,如果说我不会你信不信?

运用泰勒级数,把cosx和ln(1+x^2)展开
lim((-cosx+1-ln(1+x^2)^1/2)/x^4)
=lim[(-1+x^2/2-x^4/24+o(x^5)+1 -1/2(x^2-x^4/2+o(x^5)]/x^4
=5/24