Question

Daca x apartine intervalului (0,pi/2) si cos x=5/13 aflati sin x.

Answer 1

Bună,

x € (0;π/2) → x € CI

cos x = 5/13.

sin²x+cos²x = 1
sin²x+25/169 = 1
sin²x = 169/169-25/169
sin²x = 144/169
sin x = 12/13.


Succes!

Answer 2

x apartine (0;pi/2)=> cos>0 si sin>0
cos^2+sin^2=1=>25/169+sin^2=1=>sin^2=144/169=>sin x=12/13