The teacher will be very surprised to see your correct solution 😉
/x\ ___ 2*sin|-| = -\/ 3 \2/
Divide both parts of the equation by 2
sum
2*pi 8*pi - ---- + ---- 3 3
=
2*pi
product
-2*pi 8*pi -----*---- 3 3
=
2 -16*pi ------- 9
-16*pi^2/9
-2*pi x1 = ----- 3
8*pi x2 = ---- 3
x2 = 8*pi/3
x1 = -16.7551608191456
x2 = -54.4542726622231
x3 = 85.870199198121
x4 = 73.3038285837618
x5 = -41.8879020478639
x6 = 83.7758040957278
x7 = 33.5103216382911
x8 = 8.37758040957278
x9 = -27.2271363311115
x10 = -77.4926187885482
x11 = -90.0589894029074
x12 = 35.6047167406843
x13 = 48.1710873550435
x14 = -29.3215314335047
x15 = -102.625360017267
x16 = -366.519142918809
x17 = 10.471975511966
x18 = 58.6430628670095
x19 = -67.0206432765823
x20 = 1843.06769010601
x21 = 46.0766922526503
x22 = -14.6607657167524
x23 = -4.18879020478639
x24 = -39.7935069454707
x25 = -64.9262481741891
x26 = 272.271363311115
x27 = -2.0943951023932
x28 = -79.5870138909414
x29 = -44700.674670378
x30 = 71.2094334813686
x31 = 20.943951023932
x32 = -203.15632493214
x33 = 23.0383461263252
x34 = -92.1533845053006
x35 = 96.342174710087
x36 = -52.3598775598299
x37 = 60.7374579694027
x38 = 98.4365698124802
x38 = 98.4365698124802