Question

What is the value of cos (30° + 60°)?

(a) 1

(b) \(\frac {1}{4}\)

(c) \(\frac {3}{4}\)

(d) 0

This question was addressed to me during an interview.

My doubt is from Trigonometric Ratios of Specific Angles in chapter Trigonometry of Mathematics – Class 10

Answer 1

The correct choice is (a) 1

For explanation I would say: cos (30° + 60°) = cos (90°) = 1

The value of cos (90°) is 1