Abs(sin(x))<1 (неравенство)
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Укажите решение неравенства: Abs(sin(x))<1 (множество решений неравенства)
Решение
Подробное решение
Дано неравенство:
∣sin(x)∣<1
Чтобы решить это нер-во - надо сначала решить соотвествующее ур-ние:
∣sin(x)∣=1
Решаем:
Дано уравнение
∣sin(x)∣=1
преобразуем
∣sin(x)∣−1=0
∣sin(x)∣−1=0
Сделаем замену
w=∣sin(x)∣
Переносим свободные слагаемые (без w)
из левой части в правую, получим:
w=1
Получим ответ: w = 1
делаем обратную замену
∣sin(x)∣=w
подставляем w:
x1=26.7035380604
x2=39.2699085343
x3=20.4203521478
x4=−86.3937982346
x5=−29.8451300955
x6=−58.1194639977
x7=32.9867233135
x8=76.9690204681
x9=−51.8362786893
x10=48.6946866366
x11=−48.6946857788
x12=45.5530937308
x13=45.5530929823
x14=83.2522048888
x15=23.5619451519
x16=51.8362789032
x17=17.2787599561
x18=−64.4026497466
x19=−83.2522048211
x20=−76.9690203749
x21=−26.7035372005
x22=−70.6858343571
x23=−86.3937977431
x24=10.9955739382
x25=−17.2787590921
x26=−80.1106125782
x27=−39.2699084146
x28=29.8451303232
x29=80.1106131369
x30=−95.8185758681
x31=92.6769837789
x32=−10.9955738414
x33=−26.7035379987
x34=14.13716711
x35=70.6858352127
x36=17.2787591562
x37=−61.2610569934
x38=−7.85398149665
x39=32.9867225165
x40=7.85398174307
x41=61.2610563112
x42=−98.9601681513
x43=−4.71238862219
x44=−10.9955746401
x45=92.6769830592
x46=−70.6858351534
x47=23.561944406
x48=54.9778710948
x49=−32.9867224188
x50=−61.2610562447
x51=98.9601690454
x52=−48.6946865761
x53=86.393797887
x54=−36.1283154173
x55=95.818576063
x56=−17.2787598356
x57=89.5353901351
x58=67.5442423097
x59=−42.4115005851
x60=−32.9867232184
x61=−20.4203520061
x62=10.9955747361
x63=−98.9601689531
x64=−23.5619450115
x65=−64.4026491641
x66=73.8274274831
x67=70.6858344802
x68=89.5353908886
x69=−4.71238942125
x70=36.1283156186
x71=1.5707965729
x72=48.6946859012
x73=−92.6769829355
x74=−83.2522055723
x75=−89.5353907502
x76=−92.6769837308
x77=−1.57079643189
x78=26.7035373222
x79=58.119464398
x80=98.9601682516
x81=67.5442415587
x82=1.57079582972
x83=−67.5442421707
x84=−20.4203527083
x85=−42.4115012353
x86=42.4115007275
x87=76.9690196732
x88=83.2522056908
x89=−45.5530935911
x90=61.2610571126
x91=4.7123894842
x92=−73.8274272798
x93=−54.9778717967
x94=64.4026493072
x95=−76.9690195738
x96=4.7123887433
x97=−54.9778709963
x98=39.2699077337
x99=−14.1371668371
x100=54.9778718908
x101=−39.2699076684
x1=26.7035380604
x2=39.2699085343
x3=20.4203521478
x4=−86.3937982346
x5=−29.8451300955
x6=−58.1194639977
x7=32.9867233135
x8=76.9690204681
x9=−51.8362786893
x10=48.6946866366
x11=−48.6946857788
x12=45.5530937308
x13=45.5530929823
x14=83.2522048888
x15=23.5619451519
x16=51.8362789032
x17=17.2787599561
x18=−64.4026497466
x19=−83.2522048211
x20=−76.9690203749
x21=−26.7035372005
x22=−70.6858343571
x23=−86.3937977431
x24=10.9955739382
x25=−17.2787590921
x26=−80.1106125782
x27=−39.2699084146
x28=29.8451303232
x29=80.1106131369
x30=−95.8185758681
x31=92.6769837789
x32=−10.9955738414
x33=−26.7035379987
x34=14.13716711
x35=70.6858352127
x36=17.2787591562
x37=−61.2610569934
x38=−7.85398149665
x39=32.9867225165
x40=7.85398174307
x41=61.2610563112
x42=−98.9601681513
x43=−4.71238862219
x44=−10.9955746401
x45=92.6769830592
x46=−70.6858351534
x47=23.561944406
x48=54.9778710948
x49=−32.9867224188
x50=−61.2610562447
x51=98.9601690454
x52=−48.6946865761
x53=86.393797887
x54=−36.1283154173
x55=95.818576063
x56=−17.2787598356
x57=89.5353901351
x58=67.5442423097
x59=−42.4115005851
x60=−32.9867232184
x61=−20.4203520061
x62=10.9955747361
x63=−98.9601689531
x64=−23.5619450115
x65=−64.4026491641
x66=73.8274274831
x67=70.6858344802
x68=89.5353908886
x69=−4.71238942125
x70=36.1283156186
x71=1.5707965729
x72=48.6946859012
x73=−92.6769829355
x74=−83.2522055723
x75=−89.5353907502
x76=−92.6769837308
x77=−1.57079643189
x78=26.7035373222
x79=58.119464398
x80=98.9601682516
x81=67.5442415587
x82=1.57079582972
x83=−67.5442421707
x84=−20.4203527083
x85=−42.4115012353
x86=42.4115007275
x87=76.9690196732
x88=83.2522056908
x89=−45.5530935911
x90=61.2610571126
x91=4.7123894842
x92=−73.8274272798
x93=−54.9778717967
x94=64.4026493072
x95=−76.9690195738
x96=4.7123887433
x97=−54.9778709963
x98=39.2699077337
x99=−14.1371668371
x100=54.9778718908
x101=−39.2699076684
Данные корни
x63=−98.9601689531
x42=−98.9601681513
x30=−95.8185758681
x76=−92.6769837308
x73=−92.6769829355
x75=−89.5353907502
x4=−86.3937982346
x23=−86.3937977431
x74=−83.2522055723
x19=−83.2522048211
x26=−80.1106125782
x20=−76.9690203749
x95=−76.9690195738
x92=−73.8274272798
x46=−70.6858351534
x22=−70.6858343571
x83=−67.5442421707
x18=−64.4026497466
x65=−64.4026491641
x37=−61.2610569934
x50=−61.2610562447
x6=−58.1194639977
x93=−54.9778717967
x97=−54.9778709963
x9=−51.8362786893
x52=−48.6946865761
x11=−48.6946857788
x89=−45.5530935911
x85=−42.4115012353
x59=−42.4115005851
x27=−39.2699084146
x101=−39.2699076684
x54=−36.1283154173
x60=−32.9867232184
x49=−32.9867224188
x5=−29.8451300955
x33=−26.7035379987
x21=−26.7035372005
x64=−23.5619450115
x84=−20.4203527083
x61=−20.4203520061
x56=−17.2787598356
x25=−17.2787590921
x99=−14.1371668371
x44=−10.9955746401
x32=−10.9955738414
x38=−7.85398149665
x69=−4.71238942125
x43=−4.71238862219
x77=−1.57079643189
x82=1.57079582972
x71=1.5707965729
x96=4.7123887433
x91=4.7123894842
x40=7.85398174307
x24=10.9955739382
x62=10.9955747361
x34=14.13716711
x36=17.2787591562
x17=17.2787599561
x3=20.4203521478
x47=23.561944406
x15=23.5619451519
x78=26.7035373222
x1=26.7035380604
x28=29.8451303232
x39=32.9867225165
x7=32.9867233135
x70=36.1283156186
x98=39.2699077337
x2=39.2699085343
x86=42.4115007275
x13=45.5530929823
x12=45.5530937308
x72=48.6946859012
x10=48.6946866366
x16=51.8362789032
x48=54.9778710948
x100=54.9778718908
x79=58.119464398
x41=61.2610563112
x90=61.2610571126
x94=64.4026493072
x81=67.5442415587
x58=67.5442423097
x67=70.6858344802
x35=70.6858352127
x66=73.8274274831
x87=76.9690196732
x8=76.9690204681
x29=80.1106131369
x14=83.2522048888
x88=83.2522056908
x53=86.393797887
x57=89.5353901351
x68=89.5353908886
x45=92.6769830592
x31=92.6769837789
x55=95.818576063
x80=98.9601682516
x51=98.9601690454
являются точками смены знака неравенства в решениях.
Сначала определимся со знаком до крайней левой точки:
x0<x63
Возьмём например точку
x0=x63−101
=
−99.0601689531
=
−99.0601689531
подставляем в выражение
∣sin(x)∣<1
∣sin(−99.0601689531)∣<1
0.995004128836616 < 1
значит одно из решений нашего неравенства будет при:
x<−98.9601689531
_____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____ _____
\ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \ / \
-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------ο-------
x63 x42 x30 x76 x73 x75 x4 x23 x74 x19 x26 x20 x95 x92 x46 x22 x83 x18 x65 x37 x50 x6 x93 x97 x9 x52 x11 x89 x85 x59 x27 x101 x54 x60 x49 x5 x33 x21 x64 x84 x61 x56 x25 x99 x44 x32 x38 x69 x43 x77 x82 x71 x96 x91 x40 x24 x62 x34 x36 x17 x3 x47 x15 x78 x1 x28 x39 x7 x70 x98 x2 x86 x13 x12 x72 x10 x16 x48 x100 x79 x41 x90 x94 x81 x58 x67 x35 x66 x87 x8 x29 x14 x88 x53 x57 x68 x45 x31 x55 x80 x51
Другие решения неравенства будем получать переходом на следующий полюс
и т.д.
Ответ:
x<−98.9601689531
x>−98.9601681513∧x<−95.8185758681
x>−92.6769837308∧x<−92.6769829355
x>−89.5353907502∧x<−86.3937982346
x>−86.3937977431∧x<−83.2522055723
x>−83.2522048211∧x<−80.1106125782
x>−76.9690203749∧x<−76.9690195738
x>−73.8274272798∧x<−70.6858351534
x>−70.6858343571∧x<−67.5442421707
x>−64.4026497466∧x<−64.4026491641
x>−61.2610569934∧x<−61.2610562447
x>−58.1194639977∧x<−54.9778717967
x>−54.9778709963∧x<−51.8362786893
x>−48.6946865761∧x<−48.6946857788
x>−45.5530935911∧x<−42.4115012353
x>−42.4115005851∧x<−39.2699084146
x>−39.2699076684∧x<−36.1283154173
x>−32.9867232184∧x<−32.9867224188
x>−29.8451300955∧x<−26.7035379987
x>−26.7035372005∧x<−23.5619450115
x>−20.4203527083∧x<−20.4203520061
x>−17.2787598356∧x<−17.2787590921
x>−14.1371668371∧x<−10.9955746401
x>−10.9955738414∧x<−7.85398149665
x>−4.71238942125∧x<−4.71238862219
x>−1.57079643189∧x<1.57079582972
x>1.5707965729∧x<4.7123887433
x>4.7123894842∧x<7.85398174307
x>10.9955739382∧x<10.9955747361
x>14.13716711∧x<17.2787591562
x>17.2787599561∧x<20.4203521478
x>23.561944406∧x<23.5619451519
x>26.7035373222∧x<26.7035380604
x>29.8451303232∧x<32.9867225165
x>32.9867233135∧x<36.1283156186
x>39.2699077337∧x<39.2699085343
x>42.4115007275∧x<45.5530929823
x>45.5530937308∧x<48.6946859012
x>48.6946866366∧x<51.8362789032
x>54.9778710948∧x<54.9778718908
x>58.119464398∧x<61.2610563112
x>61.2610571126∧x<64.4026493072
x>67.5442415587∧x<67.5442423097
x>70.6858344802∧x<70.6858352127
x>73.8274274831∧x<76.9690196732
x>76.9690204681∧x<80.1106131369
x>83.2522048888∧x<83.2522056908
x>86.393797887∧x<89.5353901351
x>89.5353908886∧x<92.6769830592
x>92.6769837789∧x<95.818576063
x>98.9601682516∧x<98.9601690454
Решение неравенства на графике
/ / -pi \ /-pi pi\ /pi 3*pi\ /3*pi \\
Or|And|-oo < x, x < ----|, And|---- < x, x < --|, And|-- < x, x < ----|, And|---- < x, x < oo||
\ \ 2 / \ 2 2 / \2 2 / \ 2 //
(−∞<x∧x<−2π)∨(−2π<x∧x<2π)∨(2π<x∧x<23π)∨(23π<x∧x<∞) -pi -pi pi pi 3*pi 3*pi
(-oo, ----) U (----, --) U (--, ----) U (----, oo)
2 2 2 2 2 2
x∈(−∞,−2π)∪(−2π,2π)∪(2π,23π)∪(23π,∞)