MathDB
Problems
Contests
International Contests
IMO Longlists
1971 IMO Longlists
55
No real roots if coefficients sum to less than root 2
No real roots if coefficients sum to less than root 2
Source:
January 1, 2011
algebra
polynomial
algebra proposed
Problem Statement
Prove that the polynomial
x
4
+
λ
x
3
+
μ
x
2
+
ν
x
+
1
x^4+\lambda x^3+\mu x^2+\nu x+1
x
4
+
λ
x
3
+
μ
x
2
+
νx
+
1
has no real roots if
λ
,
μ
,
ν
\lambda, \mu , \nu
λ
,
μ
,
ν
are real numbers satisfying
∣
λ
∣
+
∣
μ
∣
+
∣
ν
∣
≤
2
|\lambda |+|\mu |+|\nu |\le \sqrt{2}
∣
λ
∣
+
∣
μ
∣
+
∣
ν
∣
≤
2
Back to Problems
View on AoPS