14 Test file number 89

  14.1 Problem number 111
  14.2 Problem number 117
  14.3 Problem number 122
  14.4 Problem number 123
  14.5 Problem number 124
  14.6 Problem number 125
  14.7 Problem number 128
  14.8 Problem number 134
  14.9 Problem number 135
  14.10 Problem number 137
  14.11 Problem number 143
  14.12 Problem number 785

Test folder name:

test_cases/4_Trig_functions/4.2_Cosine/89_4.2.2.1-a+b_cos-^m-c+d_cos-^n