Réponses

2013-10-17T19:18:57+02:00
1) tanx = sinx/cosx =>cosx = sinx/tanx => 0,4/5 = 0,08
2)sinx = tanx.cosx = 0,6
3) cosx = rac(1 - sin²x) = rac(1 - 0,64) = rac(0,36) = 0,6