WAEC Mathematics 2018 Theory — Question 10

Question 10 of 23 from the West African Examinations Council (WAEC) Mathematics 2018 Theory paper, with the correct answer and a full explanation.

6.(a) If tan x = 5/12, 0° < x < 90°, evaluate without using Mathematical tables or calculator: sin x / [(sin x)² + cos x]

Model answer

For a 5-12-13 triangle: sinx=5/13, cosx=12/13. sinx/(sin²x+cosx) = (5/13) ÷ [(25/169)+(12/13)] = (5/13) ÷ (181/169) = 65/181.

…and/or go further with premium services and No Ads.