0
\\\
A^2=47-4 \sqrt{33} +47+4 \sqrt{33} +2 \sqrt{47-4 \sqrt{33} } \sqrt{47+4 \sqrt{33} }=
\\\
=94+2 \sqrt{(47-4 \sqrt{33})(47+4 \sqrt{33} )}=94+2 \sqrt{2209-528}=
\\\
=94+2 \sqrt{1681}=94+82=176
\\\
A= \sqrt{176} =4 \sqrt{11} " alt=" \sqrt{47-4 \sqrt{33} } + \sqrt{47+4 \sqrt{33} } =A>0
\\\
A^2=47-4 \sqrt{33} +47+4 \sqrt{33} +2 \sqrt{47-4 \sqrt{33} } \sqrt{47+4 \sqrt{33} }=
\\\
=94+2 \sqrt{(47-4 \sqrt{33})(47+4 \sqrt{33} )}=94+2 \sqrt{2209-528}=
\\\
=94+2 \sqrt{1681}=94+82=176
\\\
A= \sqrt{176} =4 \sqrt{11} " align="absmiddle" class="latex-formula">