当x趋于0,(sinx⼀x)^(1⼀x²)极限是多少

2025-03-06 12:39:43
推荐回答(1个)
回答1:

设y=(sinx/x)^(1/x^2)
lny=[ln(sinx/x)]/x^2=(lnsinx-lnx)/x^2
lim(x→0)lny=lim(lnsinx-lnx)/x^2
=lim(1/tanx-1/x)/2x(洛必达法则)
=lim(x-tanx)/(2x^2tanx)
=lim(x-tanx)/2x^3(等价无穷小)
=lim(1-(secx)^2)/6x^2(洛必达法则)
=lim-(tanx)^2/6x^2
=-1/6
所以limy=e^(-1/6)