Question

From the adjoining figure, find
(i) sin x
(ii) cos y.

Answer 1

Answer:

sin x = 4/5

cos y = 12/13

Explanation:

solved in attachment

Answer 2

Sin x = 4/5

Cosy = 12/13

Explanation:

(i) Triangle BCD is a right-angled triangle with BC = 4 and CD = 3.

So BD^2 = BC^2 + CD^2

BD = root of (BC^2 + CD^2) = root of (3^2 + 4^2) = root of 25 = 5.

Sin x = BC / BD = 4 / 5

(ii) Triangle ABD is a right-angled triangle with AB = 12.

BD derived above as 5.

So AD^2 = AB^2 + BD^2

AD = root of (AB^2 + BD^2) = root of (12^2 + 5^2) = root of 169 = 13.

Cos y = BA / AD = 12 / 13