求下列极限,四到小题谢谢,定积分,谢谢 20
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(1)分母→0,极限存在,分子→0,0/0,用洛必达法则
∴原式=lim(x→0)(1+sin2x)/1=1
(2)=lim(x→0)arcsinx/2x=lim(x→0)1/2√(1-x²)=½
(3)=lim(x→0)(1-e^x²)/(2xsin2x+2x²cos2x)
=lim(x→0)(-2xe^x²)/(2sin2x+4xcosx+4xcos2x-4x²sin2x)
=lim(x→0)(-e^x²)/(2sin2x/2x+4cosx-2xsin2x)
∵lim(x→0)sin2x/2x=1
∴原极限=-1/6
(4)为∞/∞用洛必达法则
=lim(x→+∞)[2∫(0,x)e^u²du)·e^x²]/e^2x²
=lim(x→+∞)[2∫(0,x)e^u²du)]/e^x²
=lim(x→+∞)[2e^x²)]/2xe^x²
=lim(x→+∞)2/2x
=0
∴原式=lim(x→0)(1+sin2x)/1=1
(2)=lim(x→0)arcsinx/2x=lim(x→0)1/2√(1-x²)=½
(3)=lim(x→0)(1-e^x²)/(2xsin2x+2x²cos2x)
=lim(x→0)(-2xe^x²)/(2sin2x+4xcosx+4xcos2x-4x²sin2x)
=lim(x→0)(-e^x²)/(2sin2x/2x+4cosx-2xsin2x)
∵lim(x→0)sin2x/2x=1
∴原极限=-1/6
(4)为∞/∞用洛必达法则
=lim(x→+∞)[2∫(0,x)e^u²du)·e^x²]/e^2x²
=lim(x→+∞)[2∫(0,x)e^u²du)]/e^x²
=lim(x→+∞)[2e^x²)]/2xe^x²
=lim(x→+∞)2/2x
=0
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