求极限(e的3x次方-e的x方)ln(1+x)/1-cosx能教我高数么

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求极限(e的3x次方-e的x方)ln(1+x)/1-cosx能教我高数么
求极限(e的3x次方-e的x方)ln(1+x)/1-cosx
能教我高数么

求极限(e的3x次方-e的x方)ln(1+x)/1-cosx能教我高数么
lim【x→0】(e^3x-e^x)ln(1+x)/(1-cox)
=lim【x→0】[】(e^3x-e^x)]x/(x²/2)
=2lim【x→0】[(e^3x-e^x)]/x
=2lim【x→0】[(3e^3x-e^x)]/1
=2[3-1]=4


lim【x→0】(e^3x-e^x)ln(1+x)/(1-cox)
=lim【x→0】[(1+3x)-(1+x)]x/(x²/2)
=lim【x→0】(3x²)/(x²/2)
=6
答案:6