Question Detail
Question
If the value of α + β = 90° and α : β = 2 : 1, then what is the ratio of cos α to cos β?
Correct Answer
Option C is the correct answer.
Detailed Explanation
α + β = 90° and α:β = 2:1, so α = 60°, β = 30°. cos60° = 1/2, cos30° = √3/2. Ratio cosα : cosβ = (1/2) : (√3/2) = 1 : √3.
Hint
Find the actual angles first, then evaluate the cosine values.