Question Detail
Question
By Wallis' formula, evaluate ∫₀^(π/2) cos⁴x dx
Correct Answer
Option C is the correct answer.
Detailed Explanation
By Wallis' formula for an even power n=4: (3/4)(1/2)(π/2)=3π/16.
Hint
For an even power alone, Wallis' formula ends in a factor of π/2.