Rewriting Legendre's Equation for Orthogonality

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The discussion focuses on the orthogonality of Legendre's polynomials and the transformation of Legendre's equation. A user seeks clarification on how to rewrite the original Legendre differential equation into a new form. They successfully apply the product rule to derive the rewritten equation, specifically using the expression involving (1-x^2) and y'. The user expresses gratitude for the clarification received in the discussion. The conversation highlights the importance of understanding differential equations in the context of orthogonality in mathematical analysis.
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Homework Statement



i was reading on orthogonality of Legenedre's polynomials
and this equation came up

http://www.hit.ac.il/ac/files/shk_b/Differential.Equations/Orthogonality_of_Legendre_polynomials_files/img39.gif

It's a rewritten form of Legendre's equation, but i can't see how to get there
can someone explain how to get there from the original equation?

Homework Equations



Original

http://mathworld.wolfram.com/images/equations/LegendreDifferentialEquation/NumberedEquation1.gif

The Attempt at a Solution

 
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It's quite simple:

<br /> \frac{d}{dx}((1-x^{2})y&#039;)=(1-x^{2})y&#039;&#039; -2xy&#039;<br />

From the product rule using 1-x^2 and y'
 
i can't believe i didn't see that
haha thank you once again
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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