Найду корень уравнения: cos(2*x)=cos(x)
a*w^2 + b*w + c = 0
D = b^2 - 4 * a * c =
(-1)^2 - 4 * (2) * (-1) = 9
w1 = (-b + sqrt(D)) / (2*a)
w2 = (-b - sqrt(D)) / (2*a)
x1 = 0
-4*pi x2 = ----- 3
-2*pi x3 = ----- 3
2*pi x4 = ---- 3
4*pi x5 = ---- 3
x6 = 2*pi
x1 = -69.11503909537
x2 = 69.1150383780256
x3 = -62.8318529623378
x4 = 77.4926187885482
x5 = 10.471975511966
x6 = -6.28318514161788
x7 = 25.13274122338
x8 = 100.530964769014
x9 = -18.8495558711096
x10 = -73.3038285837618
x11 = 62.8318528532238
x12 = -81.6814090379303
x13 = 69.1150383295746
x14 = 81.6814091712551
x15 = 79.5870138909414
x16 = 50.2654824463501
x17 = 48.1710873550435
x18 = 98.4365698124802
x19 = 87.9645943357073
x20 = 75.3982239117447
x21 = -69.1150385967809
x22 = 14.6607657167524
x23 = -46.0766922526503
x24 = 52.3598775598299
x25 = -52.3598775598299
x26 = -4.18879020478639
x27 = -33.5103216382911
x28 = -18.8495555012277
x29 = -83.7758040957278
x30 = 25.1327411125589
x31 = -79.5870138909414
x32 = 18.8495557025416
x33 = 56.5486676119735
x34 = 54.4542726622231
x35 = -62.8318537995483
x36 = 33.5103216382911
x37 = -31.4159267013407
x38 = 12.5663700882745
x39 = -96.342174710087
x40 = -56.5486675394273
x41 = 25.1327417460082
x42 = -98.4365698124802
x43 = -35.6047167406843
x44 = 4.18879020478639
x45 = 43.9822971694142
x46 = -18.8495558410301
x47 = -94.2477794556977
x48 = -48.1710873550435
x49 = 25.1327412731354
x50 = 94.2477796093525
x51 = -71.2094334813686
x52 = 41.8879020478639
x53 = 85.870199198121
x54 = 35.6047167406843
x55 = -75.3982238575994
x56 = 31.4159267619367
x57 = -8.37758040957278
x58 = -54.4542726622231
x59 = -92.1533845053006
x60 = -37.6991118771132
x61 = 6.28318528426584
x62 = 2.0943951023932
x63 = -77.4926187885482
x64 = -90.0589894029074
x65 = 69.1150384283402
x66 = -29.3215314335047
x67 = -39.7935069454707
x68 = 92.1533845053006
x69 = -50.2654822985064
x70 = -87.9645943588266
x71 = -12.5663703884691
x72 = 83.7758040957278
x73 = -100.530964690899
x74 = -18.8495558006412
x75 = -27.2271363311115
x76 = -25.1327414474833
x77 = 96.342174710087
x78 = 8.37758040957278
x79 = 16.7551608191456
x80 = 39.7935069454707
x81 = -10.471975511966
x82 = 69.115037832119
x83 = -62.8318529503654
x84 = 37.6991120149696
x85 = 58.6430628670095
x86 = 0.0
x87 = 90.0589894029074
x88 = 43.9822969706241
x89 = 60.7374579694027
x90 = -41.8879020478639
x91 = 46.0766922526503
x92 = -85.870199198121
x93 = 12.5663704551863
x94 = -43.9822971745925
x95 = -2.0943951023932