Question

use the sum of difference formula what is sin(pi/2-5pi/3)?

Answer 1

sin(a-b) = sin a cos b - cos a sin b

sin(pi/2-5pi/3) = 1 cos(5 pi/3) - 0

= cos (5 pi/3)

= cos (2pi - (pi/3))

= cos (-pi/3)

= cos 60 deg

= 1/2