[tex]cosx= \frac{ \sqrt{3} }{2} [/tex]
x=[tex]arccos \frac{ \sqrt{3} }{2}+2k \pi , \pi dinZ [/tex] sau x=-[tex]arccos \frac{ \sqrt{3} }{2}+2n \pi [/tex]
x=π/6+2kπ sau x=-π/6+2nπ
selectam solutiile
0≤π/6+2kπ≤π/2 sau 0≤-π/6+2nπ≤π/2
-π/6≤2kπ≤π/2-π/6 sau π/6≤2nπ≤π/2+π/6
-1/12≤k≤1/6 sau 1/12≤n≤1/3
k=0 n∉Z
deci x=π/6
