一、选择题 1
若0( )lim1sinxxx,则当x0时,函数(x)与( )是等价无穷小
sin | |x B
ln(1)x C
1-cos | |x D
12x1 1
设f(x)在x=0 处存在3 阶导数,且0( )lim1tansinxf xxx则'''f (0) ( ) A
解析由洛必达法则可得30002( )'( )''( )limlimlim1tansin2cossinsincoscosxxxf xfxfxxxxxxxx42200''( )''( )limlim16cossin2coscos2 1xxfxfxxxxx 可得'''f (0)3 3
当x0时,与1x133为同阶无穷小的是( ) A
12233312333323000311(1)111133limlimlim(1)3313xxxxxxxxx选A
函数2sinf ( )lim1 (2 ) nnxxx的间断点有( )个 A
5x 时,分母 时( )0f x ,故20
5sin12lim 1 (2 ( 0
5))2nx , 20
5sin12lim 1 (2 0
5)2nx,故,有两个跳跃间断点,选C
已知( )bxxf xae在(-∞,+∞)内连续,且lim( )0xf x,则常数a,b 应满足的充要条件是( )