El profesor se sorprenderá mucho al ver tu solución correcta😉
cos(x) cos(x) 4/9 + 2*2/3 - 3 = 0
x1 = -29.845130209103
x2 = -67.5442420521806
x3 = -70.6858347057703
x4 = 64.4026493985908
x5 = -36.1283155162826
x6 = -92.6769832808989
x7 = -61.261056745001
x8 = -76.9690200129499
x9 = -98.9601685880785
x10 = -95.8185759344887
x11 = 29.845130209103
x12 = 80.1106126665397
x13 = -64.4026493985908
x14 = 36.1283155162826
x15 = 73.8274273593601
x16 = 32.9867228626928
x17 = -4.71238898038469
x18 = -39.2699081698724
x19 = 26.7035375555132
x20 = -7.85398163397448
x21 = 95.8185759344887
x22 = -17.2787595947439
x23 = -10.9955742875643
x24 = 98.9601685880785
x25 = -86.3937979737193
x26 = 92.6769832808989
x27 = -48.6946861306418
x28 = 54.9778714378214
x29 = 45.553093477052
x30 = 23.5619449019235
x31 = 76.9690200129499
x32 = -89.5353906273091
x33 = 4.71238898038469
x34 = -26.7035375555132
x35 = -80.1106126665397
x36 = 7.85398163397448
x37 = 14.1371669411541
x38 = 86.3937979737193
x39 = -45.553093477052
x40 = -83.2522053201295
x41 = 70.6858347057703
x42 = 83.2522053201295
x43 = 48.6946861306418
x44 = -20.4203522483337
x45 = 51.8362787842316
x46 = 10.9955742875643
x47 = 20.4203522483337
x48 = 1.5707963267949
x49 = 89.5353906273091
x50 = 17.2787595947439
x51 = 58.1194640914112
x52 = 61.261056745001
x53 = -32.9867228626928
x54 = -51.8362787842316
x55 = -287.455727803466
x56 = -14.1371669411541
x57 = -58.1194640914112
x58 = -42.4115008234622
x59 = -54.9778714378214
x60 = -1.5707963267949
x61 = 42.4115008234622
x62 = 39.2699081698724
x63 = 67.5442420521806
x64 = -23.5619449019235
x65 = -73.8274273593601
x65 = -73.8274273593601