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Dutch Mathematical Olympiad
1980 Dutch Mathematical Olympiad
1
1
Part of
1980 Dutch Mathematical Olympiad
Problems
(1)
1/a < x_0<2/a , x_0 is zero with smallest abs. value f(x) = x^3-ax+1
Source: Netherlands - Dutch NMO 1980 p1
1/28/2023
f
(
x
)
=
x
3
−
a
x
+
1
f(x) = x^3-ax+1
f
(
x
)
=
x
3
−
a
x
+
1
,
a
∈
R
a \in R
a
∈
R
has three different zeros in
R
R
R
. Prove that for the zero
x
o
x_o
x
o
with the smallest absolute value holds:
1
a
<
x
0
<
2
a
\frac{1}{a}< x_0 < \frac{2}{a}
a
1
<
x
0
<
a
2
algebra
polynomial
inequalities