a-ребро куба
(asqrt(2))^+a^=6^
3*a^=36
a=sqrt(12)=2sqrt(3)
cosa=asqrt(2)/6=2sqrt(3)*sqrt(2)/6=2/sqrt(6)=sqrt(2/3)
a-ребро куба
(asqrt(2))^+a^=6^
3*a^=36
a=sqrt(12)=2sqrt(3)
cosa=asqrt(2)/6=2sqrt(3)*sqrt(2)/6=2/sqrt(6)=sqrt(2/3)