1<=x^2<=1 [обл. опр. arccos] x=[-1;1] П/4-arccos(x^2)>=0 arccos(x^2)<=П/4 arccos(x^2)<=arccos(1/V2) [V-кв.корень] arccos = убывающая ф-ция x^2>=1/V2 x=(-S;-1/2^(1/4)]U[1/2^(1/4);+S) x=[-1;1] =>x=[-1;-1/2^(1/4)]U[1/2^(1/4);1]
1<=x^2<=1 [обл. опр. arccos]
x=[-1;1]
П/4-arccos(x^2)>=0
arccos(x^2)<=П/4
arccos(x^2)<=arccos(1/V2) [V-кв.корень]
arccos = убывающая ф-ция
x^2>=1/V2
x=(-S;-1/2^(1/4)]U[1/2^(1/4);+S)
x=[-1;1]
=>x=[-1;-1/2^(1/4)]U[1/2^(1/4);1]