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Meilleure réponse !
  • Utilisateur Brainly
2013-04-28T23:31:30+02:00

cos(3π/2 + π/3) cos(π/3)+ sin(3π/2 + π/3) sin(π/3)

=cos(π/3-π/2)cos(π/3)+sin(π/3-π/2)sin(π/3)

=sin(π/3)cos(π/3)-cos(π/3)sin(π/3)

=0

 

cos(3π/2 + π/3) cos(π/3)+ sin(3π/2 + π/3) sin(π/3)

=(cos(3π/2)cos(π/3)-sin(3π/2)sin(π/3))cos(π/3)+(sin(3π/2)cos(π/3)+cos(3π/2)sin(π/3))sin(π/3)

=sin(π/3)cos(π/3)-cos(π/3)sin(π/3)

=0