设lim(x趋近于0) (1/x)∫(上限x下限0)(1+sinat)^(3/t)dt=e^2,则a=

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设lim(x趋近于0) (1/x)∫(上限x下限0)(1+sinat)^(3/t)dt=e^2,则a=
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设lim(x趋近于0) (1/x)∫(上限x下限0)(1+sinat)^(3/t)dt=e^2,则a=
设lim(x趋近于0) (1/x)∫(上限x下限0)(1+sinat)^(3/t)dt=e^2,则a=

设lim(x趋近于0) (1/x)∫(上限x下限0)(1+sinat)^(3/t)dt=e^2,则a=
∵lim(x->0){[1+sin(ax)]^(3/x)}
=lim(x->0){[1+sin(ax)]^[(1/sin(ax))*(3sin(ax)/x)]}
=【lim(x->0){[1+sin(ax)]^[1/sin(ax)]}】^{lim(x->0)[3sin(ax)/x]}
=e^{lim(x->0)[3sin(ax)/x]} (应用重要极限lim(z->0)[(1+z)^(1/z)]=e)
=e^{lim(x->0)[3asin(ax)/(ax)]}
=e^{3a*lim(x->0)[sin(ax)/(ax)]}
=e^(3a) (应用重要极限lim(z->0)(sinz/z)=1)
∴lim(x->0)【(1/x)∫{[1+sin(at)]^(3/t)}dt】
=lim(x->0){[1+sin(ax)]^(3/x)} (0/0型极限,应用罗比达法则)
=e^(3a)
∵lim(x->0)【(1/x)∫{[1+sin(at)]^(3/t)}dt】=e²
∴e^(3a)=e² ==>3a=2
故 a=2/3.

2/3