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Mathematics
Mathematics
Problem
Determine the set of values of
k
k
k
for which the quadratic equation
x
2
+
2
k
x
+
(
k
+
3
)
=
0
x^{2}+2kx+(k+3)=0
x
2
+
2
k
x
+
(
k
+
3
)
=
0
has no real roots. a)
k
<
1
−
13
2
or
k
>
1
+
13
2
k<\dfrac{1-\sqrt{13}}{2}\;\text{or}\;k>\dfrac{1+\sqrt{13}}{2}
k
<
2
1
−
13
or
k
>
2
1
+
13
b)
1
−
13
2
<
k
<
1
+
13
2
\dfrac{1-\sqrt{13}}{2}<k<\dfrac{1+\sqrt{13}}{2}
2
1
−
13
<
k
<
2
1
+
13
c)
1
−
13
2
≤
k
≤
1
+
13
2
\dfrac{1-\sqrt{13}}{2}\le k\le\dfrac{1+\sqrt{13}}{2}
2
1
−
13
≤
k
≤
2
1
+
13
d)
1
−
13
4
<
k
<
1
+
13
4
\dfrac{1-\sqrt{13}}{4}<k<\dfrac{1+\sqrt{13}}{4}
4
1
−
13
<
k
<
4
1
+
13
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