Difference between revisions of "Legendre P"

From specialfunctionswiki
Jump to: navigation, search
 
(12 intermediate revisions by the same user not shown)
Line 1: Line 1:
The Legendre polynomials are [[orthogonal polynomials]] defined by the recurrence
+
The Legendre polynomials are [[orthogonal polynomials]] defined by the formula
$$P_n(x) = \dfrac{1}{2^nn!}\dfrac{d^n}{dx^n}(x^2-1)^n; n=0,1,2,\ldots$$
+
$$P_n(x) = \dfrac{1}{2^n} \displaystyle\sum_{k=0}^n {n \choose k}^2 (x-1)^{n-k}(x+1)^k.$$
 +
 
 
$$\begin{array}{ll}
 
$$\begin{array}{ll}
 
P_0(x) &= 1 \\
 
P_0(x) &= 1 \\
Line 6: Line 7:
 
P_2(x) &= \dfrac{1}{2}(3x^2-1) \\
 
P_2(x) &= \dfrac{1}{2}(3x^2-1) \\
 
P_3(x) &= \dfrac{1}{2}(5x^3-3x) \\
 
P_3(x) &= \dfrac{1}{2}(5x^3-3x) \\
 +
P_4(x) &= \dfrac{1}{8}(35x^4-30x^2+3) \\
 +
P_5(x) &= \dfrac{1}{8}(63x^5-70x^3+15x) \\
 
\vdots
 
\vdots
 
\end{array}$$
 
\end{array}$$
  
[[File:Legendrepolynomials.png|450px]]
+
<div align="center">
 +
<gallery>
 +
File:Legendrepolynomials.png|Graph of $P_n$ on $[-4,4]$ for $n=0,1,2,3,4,5$.
 +
</gallery>
 +
</div>
 +
 
 +
=Properties=
 +
[[Relationship between Legendre polynomial and hypergeometric 2F1]]<br />
 +
 
 +
{{:Orthogonal polynomials footer}}
 +
 
 +
[[Category:SpecialFunction]]

Latest revision as of 01:43, 22 June 2016

The Legendre polynomials are orthogonal polynomials defined by the formula $$P_n(x) = \dfrac{1}{2^n} \displaystyle\sum_{k=0}^n {n \choose k}^2 (x-1)^{n-k}(x+1)^k.$$

$$\begin{array}{ll} P_0(x) &= 1 \\ P_1(x) &= x \\ P_2(x) &= \dfrac{1}{2}(3x^2-1) \\ P_3(x) &= \dfrac{1}{2}(5x^3-3x) \\ P_4(x) &= \dfrac{1}{8}(35x^4-30x^2+3) \\ P_5(x) &= \dfrac{1}{8}(63x^5-70x^3+15x) \\ \vdots \end{array}$$

Properties

Relationship between Legendre polynomial and hypergeometric 2F1

Orthogonal polynomials