Question

Given: cos A = 5/13. evaluate: (1) sin A - cot A/2 tan A, (2) cot A + 1/cos A.​

Answer 1

CosA = 5/13

Therefore, as cosA = b/h

Base= 5 & hypotenuse = 13

Using pythagoras theorem will find perpendicular,

h^2 = b^2 + p^2

=> 13^2 = 5^2 + p^2

=> 169 = 25 + p^2

=> p^2 = 144

=> p= 12

(i) sin A - cotA/2 tan A

=> 12/13 - 5/24 × 12/5

=> 12/13- 1/2

=>11/26

(ii) cot A +1/cosA

=> 5/12 +13/5

=> 181/60