The teacher will be very surprised to see your correct solution 😉
2 4*sin (x) - 10*cos(x) - 8 = 0
sum
-2*pi 2*pi / / ___\\ / / ___\\ / / ___\\ / / ___\\ ----- + ---- + 2*im\atanh\\/ 3 // - 2*I*re\atanh\\/ 3 // + - 2*im\atanh\\/ 3 // + 2*I*re\atanh\\/ 3 // 3 3
=
0
product
-2*pi 2*pi / / ___\\ / / ___\\ / / ___\\ / / ___\\ ----- * ---- * 2*im\atanh\\/ 3 // - 2*I*re\atanh\\/ 3 // * - 2*im\atanh\\/ 3 // + 2*I*re\atanh\\/ 3 // 3 3
=
2 2 / / / ___\\ / / ___\\\ 16*pi *\- I*re\atanh\\/ 3 // + im\atanh\\/ 3 /// ------------------------------------------------- 9
-2*pi x_1 = ----- 3
2*pi x_2 = ---- 3
/ / ___\\ / / ___\\ x_3 = 2*im\atanh\\/ 3 // - 2*I*re\atanh\\/ 3 //
/ / ___\\ / / ___\\ x_4 = - 2*im\atanh\\/ 3 // + 2*I*re\atanh\\/ 3 //
x1 = -41.8879020478639
x2 = -79.5870138909414
x3 = -67.0206432765823
x4 = 2.0943951023932
x5 = 73.3038285837618
x6 = -83.7758040957278
x7 = -46.0766922526503
x8 = 67.0206432765823
x9 = 85.870199198121
x10 = 77.4926187885482
x11 = -23.0383461263252
x12 = 33.5103216382911
x13 = -10.471975511966
x14 = -14.6607657167524
x15 = -85.870199198121
x16 = -4.18879020478639
x17 = -60.7374579694027
x18 = -92.1533845053006
x19 = -58.6430628670095
x20 = 90.0589894029074
x21 = 4.18879020478639
x22 = 146.607657167524
x23 = -450.294947014537
x24 = -343.480796792484
x25 = 23.0383461263252
x26 = -71.2094334813686
x27 = -39.7935069454707
x28 = 10.471975511966
x29 = 27.2271363311115
x30 = 16.7551608191456
x31 = -64.9262481741891
x32 = -73.3038285837618
x33 = -54.4542726622231
x34 = -1296.43056838139
x35 = -8.37758040957278
x36 = 92.1533845053006
x37 = -77.4926187885482
x38 = -48.1710873550435
x39 = 48.1710873550435
x40 = -148.702052269917
x41 = -98.4365698124802
x42 = 96.342174710087
x43 = -16.7551608191456
x44 = 58.6430628670095
x45 = 20.943951023932
x46 = 83.7758040957278
x47 = 14.6607657167524
x48 = -29.3215314335047
x49 = 29.3215314335047
x50 = -90.0589894029074
x51 = 60.7374579694027
x52 = 54.4542726622231
x53 = -96.342174710087
x54 = 35.6047167406843
x55 = 39.7935069454707
x56 = 41.8879020478639
x57 = -8720441.26541496
x58 = -20.943951023932
x59 = -2.0943951023932
x60 = 46.0766922526503
x61 = -27.2271363311115
x62 = 64.9262481741891
x63 = 98.4365698124802
x64 = -35.6047167406843
x65 = -52.3598775598299
x66 = 71.2094334813686
x67 = -33.5103216382911
x68 = 4500.85507504298
x69 = 8.37758040957278
x70 = 79.5870138909414
x71 = 52.3598775598299
x71 = 52.3598775598299