Mark the Correct alternative in the following:
The value of cos 52o + cos 68o + cos 172o is
cos 52° + cos 68° + cos 172°
= (cos 52° + cos 68°) + cos 172°
= 2cos 60° cos 8° + cos (180° - 8°)
= 2 ⋅ 1/2 ⋅ cos 8° - cos 8°
= cos 8° - cos 8°
= 0 (Ans)