28 Test file number 141

  28.1 Problem number 421
  28.2 Problem number 422
  28.3 Problem number 428
  28.4 Problem number 429
  28.5 Problem number 669
  28.6 Problem number 734
  28.7 Problem number 740

Test folder name:

test_cases/4_Trig_functions/4.7_Miscellaneous/141_4.7.7_Trig_functions