cos ( -1500°) =______________
A. 1/2
B. -1/2
C. √3/2
D. -√3/2
I have been asked this question during an interview.
This is a very interesting question from Trigonometric Functions topic in chapter Trigonometric Functions of Mathematics – Class 11
The correct answer is A. 1/2
Explanation: cos(-1500°) = cos(1500°) {cos(-x) = cos x}
= cos (4*360° + 60°) = cos 60° = 1/2. {cos (2nπ+x) = cos x}