lim(sin∧3)tanx 1-cosx∧2

(tanx-sinx)/sin³x=(sinx/cosx-sinx)/sin³x=(1/cosx-1)/sin²x=[(1-cosx)/cosx]/(1-cos²

lim(tan^3(3x)/(X^2sin(2x))=(27/2)*lim{[tan^3(3x)/(3x)^3]*[2X/sin(2x)]}=27/2或用洛彼得法则

limx[sinln(1+3/x)-sinln(1+1/x)],x趋近于无穷大=lim[sinln(1+3/x)-sinln(1+1/x)]/(1/x)拆项sin(x)~xln(1+3/x)~3/x注

因为1+tanx1−tanx=2 010，则1cos2x+tan2x=1cos2x+sin2xcos2x=1+sin2xcos2x=(sinx+cosx)2cos2x−sin2x=cosx+

先看第一步tanx-sinx就是公式变形,sinx=tanx*cosx,然后代进去,tanx-tanx*cosxtanx(1-cosx),然后tanx等价于x,1-cosx等价于2x^2,sin^3x

limsin3x/tan5x=lim3cos3x/[5(sec5x)^2]=(3/5)limcos3x(cos5x)^2=(3/5)cos3π(cos5π)^2=-3/5limtanx/x=limx/

0比0型极限,请用洛必达法则.即,分式上下分别求导.[sinx-sin(sinx)]‘=cosx-cosxcos(sinx),x→0,→1-1*1=0(sinx)^3=3cosxsinx^2=0继续使

令a=π-x则a趋于0sin3x=sin(3π-3a)=sin3asin2x=sin(2π-2a)=-sin2a所以原式=-lim(a→0)sin3a/sin2asin3a和sin2a的等价无穷小是3

令t=1\x原式=limt→0(3/t-1)/(1/t*sint^2)=limt→0(3/t-1)/(1/t*t^2)-----这里用到无穷小量有关知识=limt→0（3-t）=3

令t=arcsinx则x=sintx→0时t→0所以原式=(等价无穷小代换)lim(x-arcsinx)/x³=lim(sint-t)/sin³t=lim(sint-t)/t&su

1,lim(x→∞)(sinx/x+100)=0+100=1002,lim(x→∞)xtan(1/x)=lim(x→∞)tan(1/x)/(1/x)=lim(x→∞)(-1/x^2)sec²

由和差化积公式分子=2sin[(x^3+x^2)/2]cos[(x^3+x^2-2x)/2]x→0,则(x^3+x^2)/2→0,sin则(x^3+x^2)/2和(x^3+x^2)/2是等价无穷小而c

使用等价无穷小即可求解因为x→0时,e^x-1~x1-cosx~x^2/2所以原式=lim(sinx)^3/(x*x^2/2)=2lim(sinx)^3/x^3又x→0时,sinx~x所以原式=2

lim（x→0）(x-sin(3x))/(x+sinx)（这是0/0型,运用洛必达法则）＝lim（x→0）(1-3cos3x)/(1+cosx)=-1

原式=lim(x->0)[(sinx/cosx-sinx)/sin³x]=lim(x->0)[(1-cosx)/(sin²xcosx)]=lim(x->0)[2sin²(

lim(x趋向于3)sin(x-3)/(x*x-9)=lim(x趋向于3)sin（x-3）/[(x-3)(x+3)]=[lim(x趋向于3)sin（x-3）/(x-3)]*[lim(x趋向于3)1/(

lim【n→∞】(2n²-3n+1)/(n+1)×sin(1/n)=lim【n→∞】(2n²-3n+1)/(n+1)×(1/n)=lim【n→∞】(2n²-3n+1)/(

当x趋于0时,tanx-sinx=tanx*(1-cosx),而tanx等价于sinx,1-cosx等价于0.5(sinx)^2,那么tanx*(1-cosx)等价于0.5(sinx)^3所以lim(

limx→0(x∧2cscxsin(1/x))=limx→0(x^2sin(1/x))/sinx=limx→0(xsin(1/x))(x/sinx)=limx→0(xsin(1/x))limx→0(x