Question

What is the absolute value of 4-2i?

Answer 1

2
√
5
,
8
and
√
58
Explanation:
given a complex number
x
+
y
i
then the absolute value is
∙
x
|
x
+
y
i
|
=
√
x
2
+
y
2
4
+
2
i
has
x
=
4
and
y
=
2
⇒
|
4
+
2
i
|
=
√
4
2
+
2
2
=
√
20
=
2
√
5
8
i
has
x
=
0
and
y
=
8
⇒
|
8
i
|
=
√
0
2
+
8
2
=
8
−
3
+
7
i
has
x
=
−
3
and
y
=
7
⇒
|
−
3
+
7
i
|
=
√
(
−
3
)
2
+
7
2
=
√
58