问题标题:
1/sin^2x-1/x^2x趋向0求极限
问题描述:
1/sin^2x-1/x^2x趋向0求极限
单征回答:
lim(1/sin^2x-1/x^2)
=lim(x^2-sin^2x)/x^4
=lim(2x-2sinxcosx)/4x^3
=lim(2x-sin2x)/4x^3
=lim(2-2cos2x)/12x^2
=lim4sin2x/24x
=4/12=1/3
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