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Mathematics
Mathematics
Problem
If
a
>
0
a>0
a
>
0
and
z
=
(
1
+
i
)
2
a
−
i
z=\frac{(1+i)^2}{a-i}
z
=
a
−
i
(
1
+
i
)
2
has magnitude
2
5
\sqrt{\frac{2}{5}}
5
2
, then
z
ˉ
\bar{z}
z
ˉ
is equal to (a)
1
5
−
3
5
i
\frac{1}{5}-\frac{3}{5}i
5
1
−
5
3
i
(b)
−
1
5
−
3
5
i
-\frac{1}{5}-\frac{3}{5}i
−
5
1
−
5
3
i
(c)
−
1
5
+
3
5
i
-\frac{1}{5}+\frac{3}{5}i
−
5
1
+
5
3
i
(d)
−
3
5
−
1
5
i
-\frac{3}{5}-\frac{1}{5}i
−
5
3
−
5
1
i
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