求下列极限:lim(x→无穷大)xcos2⼀x

2025-06-29 08:54:57
推荐回答(1个)
回答1:

lim(x→无穷大)xcos2/x
=cos(2/x)/1/x
=[1-2(sin1/x)平方]/(1/x)
=x-2(sin1/x)/(1/x)*(sin1/x)
=x-2sin1/x
=无穷大