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Fungrim entry: 227d60

(Pn ⁣(x))2Pn1 ⁣(x)Pn+1 ⁣(x)>0{\left(P_{n}\!\left(x\right)\right)}^{2} - P_{n - 1}\!\left(x\right) P_{n + 1}\!\left(x\right) > 0
Assumptions:nZ1  and  x(1,1)n \in \mathbb{Z}_{\ge 1} \;\mathbin{\operatorname{and}}\; x \in \left(-1, 1\right)
TeX:
{\left(P_{n}\!\left(x\right)\right)}^{2} - P_{n - 1}\!\left(x\right) P_{n + 1}\!\left(x\right) > 0

n \in \mathbb{Z}_{\ge 1} \;\mathbin{\operatorname{and}}\; x \in \left(-1, 1\right)
Definitions:
Fungrim symbol Notation Short description
Powab{a}^{b} Power
LegendrePolynomialPn ⁣(z)P_{n}\!\left(z\right) Legendre polynomial
ZZGreaterEqualZn\mathbb{Z}_{\ge n} Integers greater than or equal to n
OpenInterval(a,b)\left(a, b\right) Open interval
Source code for this entry:
Entry(ID("227d60"),
    Formula(Greater(Sub(Pow(Parentheses(LegendrePolynomial(n, x)), 2), Mul(LegendrePolynomial(Sub(n, 1), x), LegendrePolynomial(Add(n, 1), x))), 0)),
    Variables(n, x),
    Assumptions(And(Element(n, ZZGreaterEqual(1)), Element(x, OpenInterval(-1, 1)))))

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Copyright (C) Fredrik Johansson and contributors. Fungrim is provided under the MIT license. The source code is on GitHub.

2021-03-15 19:12:00.328586 UTC