1.NounFor a complex number
a
+
b
i
{\displaystyle a+bi}
, the principal square root of the sum of the squares of its real and imaginary parts,
a
2
+
b
2
{\displaystyle {\sqrt {a^{2}+b^{2}}}}
. Denoted by vertical bars
|
|
{\displaystyle |\,|}
.
"The absolute value
|
x
|
{\displaystyle |x|}
of a real number
x
{\displaystyle x}
is
x
2
{\displaystyle {\sqrt {x^{2}}}}
, which is equal to
x
{\displaystyle x}
if
x
{\displaystyle x}
is non-negative, and
−
x
{\displaystyle -x}
if
x
{\displaystyle x}
is negative."