Question

given cosA=7/25 and A lies between 450°and 540°find sin A/2and cosA/2​

Answer 1

Answer:

cos A = -7/25

(sin A/2)^ 2 = (1 - cosA) /2

= 9/25

sin A/2 = 3/5

(cos A/2)^2 = (1 + cosA) /2

= 16/25

cos A/2 = 4/5