cos (17π/3) =______________ A. 1/2 B. -1/2 C. √3/2 D. -√3/2 This

cos-17p-3-a-1-2-b-1-2-c-3-2-d-3-2-this

cos (17π/3) =______________

A. 1/2

B. -1/2

C. √3/2

D. -√3/2

This question was addressed to me in an interview for job.

This key question is from Trigonometric Functions in chapter Trigonometric Functions of Mathematics – Class 11

Right answer is A. 1/2

Easiest explanation: cos (17π/3) = cos (2π*3 – π/3)

{cos (2nπ-x)=cos x}

= cos(π/3) = 1/2.