1-cosx的等价无穷小为0.5x怎么证明
问题描述:
1-cosx的等价无穷小为0.5x怎么证明
答
x→0时(1-cosx)/(x^2/2)
=2[sin(x/2)]^2/(x^2/2)
→1,
∴1-cosx与x^2/2是等价无穷小.