求limx趋向0(1-cosx^2)/[(x^2)*sinx^2]

Question

求lim x趋向0 (1-cosx^2)/[(x^2)*sinx^2]

Answer 1

1-cos(x^2)~1/2·(x^2)^2=1/2·x^4
sinx^2~x^2
原式=lim[1/2·x^4/(x^2·x^2)]=1/2