Răspunsuri

  • Utilizator Brainly
2014-02-24T12:58:57+02:00
Sin²A+cos²A=1 ⇒ 1/4+cos²A=1 ⇒ cosA=√(1-1/4)=√3/2.
2014-02-24T12:59:24+02:00
Cos²A+sin²A=1
sin²A= 1/4
cos²A=1-sin²A=1-1/4=3/4 ⇒cosA = √3/2