= 3cos(2π-β) - sin(π/2+β)/2cos(β-π)
= 3cos(-β) - sin(π/2+β)/2cos(β-π)
= 3cos(-β) - sin(π/2)cos(β) - cos(π/2)sin(β)/2cos(β+π)
= 3cos(-β) - cos(β)/2cos(β+π)
= 3cos(-β) - cos(β)/2(-cos(β))
= 3cos(-β) + 1/2cos(β)
= 3cos(β) + 1/2cos(β)
= (3 + 1/2)cos(β)
= 7/2cos(β)
Therefore, the simplified expression is 7/2cos(β).
= 3cos(2π-β) - sin(π/2+β)/2cos(β-π)
= 3cos(-β) - sin(π/2+β)/2cos(β-π)
= 3cos(-β) - sin(π/2)cos(β) - cos(π/2)sin(β)/2cos(β+π)
= 3cos(-β) - cos(β)/2cos(β+π)
= 3cos(-β) - cos(β)/2(-cos(β))
= 3cos(-β) + 1/2cos(β)
= 3cos(β) + 1/2cos(β)
= (3 + 1/2)cos(β)
= 7/2cos(β)
Therefore, the simplified expression is 7/2cos(β).