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Mathematics
Mathematics
Problem
If
f
(
x
)
=
x
3
+
4
x
2
+
λ
x
+
1
f(x) = x^3 + 4x^2 + \lambda x + 1
f
(
x
)
=
x
3
+
4
x
2
+
λ
x
+
1
is a monotonically decreasing function of
x
x
x
in the largest possible interval
(
−
2
,
−
2
3
)
\left(-2, -\frac{2}{3}\right)
(
−
2
,
−
3
2
)
then : (A)
λ
=
4
\lambda = 4
λ
=
4
(B)
λ
=
2
\lambda = 2
λ
=
2
(C)
λ
=
−
1
\lambda = -1
λ
=
−
1
(D)
λ
\lambda
λ
has no real values
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