Question

一道高数求极限的题在线等

Answer 1

let
y=1/x
lim(x->∞) [ cos(1/x)]^x^2
=lim(y->0) ( cosy)^(1/y^2)
=lim(y->0) ( 1- (1/2)y^2)^(1/y^2)
=e^(-1/2)