Fermi
·
Concept Library
·
Courses
·
Books
·
Problems
·
Simulations
·
Math Wiki
·
High School
Fermi
›
Problems
Problem
Problem
Let
a
∈
R
a \in \mathbb{R}
a
∈
R
and let
f
:
R
→
R
f : \mathbb{R} \to \mathbb{R}
f
:
R
→
R
be given by
f
(
x
)
=
x
5
−
5
x
+
a
f(x) = x^5 - 5x + a
f
(
x
)
=
x
5
−
5
x
+
a
. Then, a.
f
(
x
)
f(x)
f
(
x
)
has three real roots, if
a
>
4
a > 4
a
>
4
b.
f
(
x
)
f(x)
f
(
x
)
has only one real root, if
a
>
4
a > 4
a
>
4
c.
f
(
x
)
f(x)
f
(
x
)
has three real roots, if
a
<
−
4
a < -4
a
<
−
4
d.
f
(
x
)
f(x)
f
(
x
)
has three real roots, if
−
4
<
a
<
4
-4 < a < 4
−
4
<
a
<
4
Browse the problem library