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Mathematics
Mathematics
Problem
Consider the polynomial function
r
(
x
)
=
−
x
4
+
4
x
3
r(x)=-x^{4}+4x^{3}
r
(
x
)
=
−
x
4
+
4
x
3
. On which open interval is
r
r
r
increasing and concave down? a)
(
3
,
∞
)
(3,\infty)
(
3
,
∞
)
b)
(
2
,
3
)
(2,3)
(
2
,
3
)
c)
(
0
,
2
)
(0,2)
(
0
,
2
)
d)
(
2
,
∞
)
(2,\infty)
(
2
,
∞
)
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