lim x趋向于无穷 2^n sin(x/2^n)
问题描述：
lim x趋向于无穷 2^n sin(x/2^n)
答
x趋向于无穷时,sin(x/2^n)等价于x/2^n
所以lim2^n sin(x/2^n)=lim2^n *x/2^n=x=无穷