ProofWiki:Potw

Current Proof of The Week  Variance as Expectation of Square minus Square of Expectation 

HOW TO USE THIS PAGE

 * 1. Select the proof P you want to put up as POTW.
 * 2. Edit P to put this at the top:


 *  


 * replacing   with today's date.


 * 3. Edit the previous POTW to change:
 *  
 * to:
 *  


 * 4. Edit this page to:
 * (a) add the old POTW to the top of the list;
 * (b) put the new POTW into the two places where the last one was.

Previous proofs of the week

 * Integrating Factors for First Order Equations
 * Cassini's Identity
 * Bayes' Theorem
 * Solution to Linear First Order Ordinary Differential Equation
 * Basis Representation Theorem
 * Odd Number Theorem
 * Euler's Number is Irrational
 * Kleene's Normal Form Theorem
 * Picard's Existence Theorem
 * Fundamental Theorem of Arithmetic
 * Peak Point Lemma
 * Closed Form for Triangular Numbers
 * Existence of Euler-Mascheroni Constant
 * Cauchy Mean Value Theorem
 * Sum of Angles of Triangle Equals Two Right Angles
 * Monotone Convergence Theorem
 * Bhaskara's Lemma
 * Conjugacy Class Equation
 * Fermat's Christmas Theorem
 * L'Hôpital's Rule
 * Banach-Tarski Paradox
 * Rolle's Theorem
 * Heron's Formula
 * Area of a Circle
 * Zero and One are the only Consecutive Perfect Squares
 * Chinese Remainder Theorem
 * Sigma Function is Multiplicative
 * Prime Divides Factors
 * Lebesgue's Number Lemma
 * Cardan's Formula
 * Area of a Square
 * Westwood's Puzzle
 * Integration by Parts
 * Euclid's Lemma
 * Combination Theorem for Sequences
 * Russell's Paradox
 * Derivative of a Composite Function
 * First Sylow Theorem
 * Euler Phi Function
 * Fundamental Principle of Counting
 * Partition Equation
 * Archimedean_Principle
 * Pascal's Rule
 * Division Theorem
 * Lagrange's Theorem
 * Quadratic Equation
 * Handshake Lemma
 * Cantor-Bernstein-Schroeder Theorem
 * Euler's formula
 * Fermat's Little Theorem
 * Cantor's Theorem
 * There are Infinitely many primes
 * The Binomial Theorem
 * There exist irrational a and b such that a^b is rational
 * Law of Cosines
 * Pythagoras's Theorem