Pre Calculus

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

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asked by Josh
  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

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    posted by Damon

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