Calculo
limx→0sen XX=1
=1
721. Calcular limx→0sen 3xx=00
limx→03·sen 3x3x=3·1=3
722. Calcular limx→0sen (7x)sen (3x)*1x
limx→01xsen (7x)1xsen 3x= limx→0sen (7x)xsen (3x)x= limx→07sen (7x)7x3sen (3x)3x=7(1)3(1)=73
723. Calcular. limx→0sen2 x2x2=00
limx→0sen x2X·sen x2X=limx→0sen x22x2·sen x22x2=12·1·12·1=14
724. Calcular limx→0tanxx=00
limx→0senxcosxx= limx→0senxx·cosx=limx→01cosx=11=1
725. Calcular limx→0sen(πx)sen (3πx)=00
Si Sen 3A=3Sen A-4Sen3 A
limx→0sen (πx)3sen πx-4sen3 (πx)= limx→0sen πxsen πx3-4sen2 πx= limx→013-4sen2(πx)=13-4·0= 13-0=13
limt→0πt·sen t=limt→0πsen tt= π·1=π
726. Calcular limn→∞n·sen πn
πn=t ; n→∞
πt=n ; t→0
727. Calcular limx→01- cos xx2=00
limx→01- cos x·1+ cos xx2·1∓cos x=limx→012- cos2 xx2·1+ cos x=limx→0sen2xx2·1+ cos x=limx→0sen xx·sen xx·1+ cos x= 1·11+1=1·12=12
728. Calcular limx→0sen xtanx=00
limx→0sen x1senxcosx= limx→0sen x·cosxsen x=limx→0cosx=cos0=1
729. Calcular limx→0x·cotx=0·∞
limx→0x·cosxsen x=limx→0xsen x·limx→0cosx=limx→0xxsen xx·1=limx→0xx·1=11=1
730. Calcular limx→0sen (2x)sen(5x)=00
limx→02x·tan (2x)2x5x·sen(5x)5x=limx→02x·15x·1=25
731. Calcular limx→0x1-cosx=00
Senx2=1-cosx2=Sen x2=1-cosx2= 2·sen x=1-cosx
limx→0x2·senx2=limx→0x2·x2·senx2x2=limx→0x2·x2·1=122=22
732. Calcular limx→πsen xx-π=00
x-π=V ;x→π
x=V+π ;V→0
limV→0sen V+πV
Si sen A+B=sen A·cosB+sen B·cosA
limV→0sen V·cosπ + sen π·cosVV=limV→0sen V-1+0V=limV→0-sen VV=-1
733. Calcular limx→π2cosxx-π2=00
x-π2=t ;x→π2
x=t+π2 ;t→0
limx→π2cos t+π2t
limx→π2cost·cosπ2-sen t·sen π2t=limx→π20-sen tt=limx→π2-sen tt=-1
734. Calcular limx→-2tanπxx+2=00
x+2=t ;x→-2
x=t-2 ;t→0
limx→-2tanπ(t-2)t=limx→-2tan(πt-2π)t=
tanA-B= tanA-tanB1+tanA·tanB
limx→-2tanπt-tan2π1+tanπt·tan2πt=limx→-2tanπt-01+tanπt·0t=limx→-2tanπtt=limx→-2πtanπtπt=π·1=π
735. Calcular limx→1(1-x)tanπx2=0·∞
1-x=t ;x→1
x=1-t ;t→0
limx→1ttanπ21-t=limx→1t·tanπ2-πt2=limx→1t·senπ2-πt2cosπ2-πt2=limx→1t·senπ2-πt2cosπ2-πt2=limx→1t·senπ2·cosπt2-sen πt2·cosπ2 cosπ2 ·cosπt2+senπ2sen πt2·=limx→1t·1·cosπt20+sen πt2 =limx→1tsen πt2·limx→1cosπt2=limx→1tπt2sen πt2πt2=limx→1tπt2=1π2=2π
736. Calcular lím Cotag 2x. Cotag (π2- x)
X 0
limx→1cos2x∙senπ2- xsen 2x ∙sen π2- x=
limx→1cos2x [cosπ2cosx +senπ2 ∙sen x]sen 2x [sen π2cosx –sen xcosπ2=
limx→1cos2x[0+sen x]sen 2x [cosx –0]= limx→1 cos2x∙senxsen 2x∙sen x
limx→1cos2x sen 2x = limx→1 x ∙ sen xx 2x sen 2x2x = x ∙1 2x∙1= 12
737.- Calcular limx→1 tag πx2 a ∙sen x-a2
x-a2=t ; x→a
x-a=2 t limx→0 tag π (2t+a)2 a ∙sen t
x=2t+a ; t→0
limx→0 tag 2πt2a+πa2a∙sen
limx→0 tag πta+π2 ∙sen t= limx→0 sen πta+π2cosπta+π2 ∙sen t =
limx→0sen πtαcosπ2 +sen π2 cosπtαcosπtα ∙cosπ2- sen πtαsenπ2 ∙sen t =
limx→00+ cosπtα 0- sen πtα ∙sen t =
limx→0 sen t - sen πtα ∙ limx→0 cosπtα=
limx→0t sen tt - πtα sen πtαπtα = 1πα= -απ
738.- Calcular limx→a sen x-sen ax-a
Si senA – sen B = 2 senA-B2cosA+B2
limx→a2 sen x-a2 cosx-a2x-a=
2 lim x→a2 senx-a2 2 ∙x-a2∙ lim x→a cosx-a2
2/2 lim x→a sen x-a2 x-a2∙ cosa+a2=
1. 1. cos2a2= 1.cosa =cosa
739.- Calcular lim x→a cosx-cosax-a
Si cos A – cos B = - 2 sen A+B2 sen A-B2
lim x→a – 2 sen x+a2 sen x-a2x-a=
-2 lim x→a sen x+a2 1∙ lim x→a sen x+a2 x-a =
- 2 sen a+a2∙lim x→a sen x+a2 2 x+a2=
- 2 sen 2x2∙lim x→a sen t 2 t=...
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