The teacher will be very surprised to see your correct solution 😉
x1 = -acos(-3/10) + 2*pi
x2 = acos(-3/10)
x2 = acos(-3/10)
sum
-acos(-3/10) + 2*pi + acos(-3/10)
=
2*pi
product
(-acos(-3/10) + 2*pi)*acos(-3/10)
=
(-acos(-3/10) + 2*pi)*acos(-3/10)
(-acos(-3/10) + 2*pi)*acos(-3/10)
x1 = 60.9563640909856
x2 = 1.87548898081029
x3 = 4.40769632636929
x4 = -8.15867428798988
x5 = -48.3899934766264
x6 = 23.2572522479081
x7 = -58.4241567454266
x8 = -77.2737126669653
x9 = -52.140971438247
x10 = -39.5746008238878
x11 = -23.2572522479081
x12 = 45.8577861310674
x13 = -29.5404375550876
x14 = 20.7250449023491
x15 = -45.8577861310674
x16 = 89.8400832813245
x17 = 10.6908816335489
x18 = -10.6908816335489
x19 = 58.4241567454266
x20 = 39.5746008238878
x21 = -142.63777308432
x22 = 14.4418595951695
x23 = -42.1068081694468
x24 = 48.3899934766264
x25 = 54.673178783806
x26 = -67.2395493981652
x27 = 8.15867428798988
x28 = 73.5227347053447
x29 = -16.9740669407285
x30 = 83.5568979741449
x31 = -70.9905273597857
x32 = 29.5404375550876
x33 = 70.9905273597857
x34 = -54.673178783806
x35 = -86.0891053197039
x36 = -33.2914155167082
x37 = 98.6554759340631
x38 = -73.5227347053447
x39 = 92.3722906268835
x40 = 64.7073420526062
x41 = 284.618827803892
x42 = -27.0082302095286
x43 = 33.2914155167082
x44 = -4.40769632636929
x45 = -14.4418595951695
x46 = 96.1232685885041
x47 = -83.5568979741449
x48 = -35.8236228622672
x49 = 79.8059200125243
x50 = -92.3722906268835
x51 = 27.0082302095286
x52 = -1.87548898081029
x53 = -60.9563640909856
x54 = 86.0891053197039
x55 = -98.6554759340631
x56 = -96.1232685885041
x57 = 42.1068081694468
x58 = -79.8059200125243
x59 = 35.8236228622672
x60 = -89.8400832813245
x61 = 52.140971438247
x62 = 16.9740669407285
x63 = 67.2395493981652
x64 = 77.2737126669653
x65 = -64.7073420526062
x66 = -20.7250449023491
x66 = -20.7250449023491