Réponses

  • Utilisateur Brainly
2013-07-31T09:27:55+02:00

sinx/sin³(x) + Cosx/Cos³(x)

=1/cos²(x)+1/sin²(x)

=(cos²(x)+sin²(x))/(sin²(x)cos²(x)*2)

=2/(4*sin²(x)cos²(x))

=2/(sin(2x))²