Найду корень уравнения: cos(2x)=1/2
pi x1 = -- 6
5*pi x2 = ---- 6
x1 = -19.3731546971371
x2 = 3.66519142918809
x3 = 78.0162175641465
x4 = 93.7241808320955
x5 = -43.4586983746588
x6 = -3.66519142918809
x7 = -87.4409955249159
x8 = -82.2050077689329
x9 = 131.423292675173
x10 = -69.6386371545737
x11 = -31.9395253114962
x12 = 68.5914396033772
x13 = -71.733032256967
x14 = 30.8923277602996
x15 = 0.523598775598299
x16 = -9.94837673636768
x17 = 56.025068989018
x18 = 66.497044500984
x19 = 91.6297857297023
x20 = -41.3643032722656
x21 = -12.0427718387609
x22 = 27.7507351067098
x23 = -217.293491873294
x24 = -81.1578102177363
x25 = -16.2315620435473
x26 = -5.75958653158129
x27 = -90.5825881785057
x28 = 52.8834763354282
x29 = -91.6297857297023
x30 = 16.2315620435473
x31 = -40.317105721069
x32 = -34.0339204138894
x33 = -21.4675497995303
x34 = 38.2227106186758
x35 = -84.2994028713261
x36 = 22.5147473507269
x37 = 41.3643032722656
x38 = 62.3082542961976
x39 = 82.2050077689329
x40 = 85.3466004225227
x41 = -49.7418836818384
x42 = -46.6002910282486
x43 = -85.3466004225227
x44 = -56.025068989018
x45 = 19.3731546971371
x46 = -97.9129710368819
x47 = -65.4498469497874
x48 = 44.5058959258554
x49 = 53.9306738866248
x50 = 84.2994028713261
x51 = -7272.26339428477
x52 = -53.9306738866248
x53 = 125.140107367993
x54 = 97.9129710368819
x55 = 75.9218224617533
x56 = 49.7418836818384
x57 = 63.3554518473942
x58 = -18.3259571459405
x59 = 5.75958653158129
x60 = -100.007366139275
x61 = -47.6474885794452
x62 = -25.6563400043166
x63 = 88.4881930761125
x64 = -27.7507351067098
x65 = 2.61799387799149
x66 = 100.007366139275
x67 = 12.0427718387609
x68 = 31.9395253114962
x69 = 24.60914245312
x70 = -68.5914396033772
x71 = 25.6563400043166
x72 = 96.8657734856853
x73 = -2685.53812004368
x74 = -62.3082542961976
x75 = -60.2138591938044
x76 = -2.61799387799149
x77 = 74.8746249105567
x78 = 90.5825881785057
x79 = 69.6386371545737
x80 = -93.7241808320955
x81 = 46.6002910282486
x82 = -24.60914245312
x83 = 40.317105721069
x84 = 60.2138591938044
x85 = -75.9218224617533
x86 = 8.90117918517108
x87 = -63.3554518473942
x88 = 18.3259571459405
x89 = -13.0899693899575
x90 = -78.0162175641465
x91 = 9.94837673636768
x92 = -1152.44090509186
x93 = 47.6474885794452
x94 = 71.733032256967
x95 = -35.081117965086
x96 = 34.0339204138894
x97 = -38.2227106186758