同济大学高等数学 一、
sin2(x?1)1、limx?1x2?1;
2sin?x?1?cos?x?1??0解一: 原式?limx?12x
sin?x?1?sin?x?1?原式?limlim?0解二: x?1x?1x?1x?12xlim2、x?0sin23x 解一:
2x13x11原式?lim?lim?lim? x?06sin3xcos3x9x?0sin3xx?0cos3x9解二:
sin3x~3x2xx1原式?lim?lim?x?06sin3xcos3xx?09xcos3x9
xtan2xlim3、x?0sin23x
解:
原式tan2x~2x,sin3x~3x=limx?02x22?3x?2?9
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xlim4、x?0ln(1?x)
1原式?lim?lim?1?x??1x?0x?01解一: 1?x解二:
原式?limx?01ln?1?x?x1x1??1lne
?x?2?lim?5、x???x??
?2?原式?lim?1??x??解一:?x?解二:
x?2xlnxlimln?x?2??lnxx?111?limx?2?2xx???xx????2?2?e?2
原式?limex???e?2x???e ?e
?2xlimx??x?2?e精选
3?2x??6、limx?1解
令t?x?11x?1 一
1????2?2t:
原式?lim?1?2t?t?0?e?2
解二:
原式?lim[1?(2?2x)]x?11g(?2)2?2x??2 {lim[1?(2?2x)]x?112?2x?2} ?ex?sinxlim37、x?0 x1?cosxsinx1原式?lim?lim?2解:x?0x?06x3x6
1??1lim??8、x?1?x?1lnx??
解:
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