index: click on a letter A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A to Z index index: subject areas numbers & symbols sets, logic, proofs geometry algebra trigonometry advanced algebra & pre-calculus calculus advanced topics probability & statistics real world applications multimedia entries

 QED An abbreviated Latin phrase used to indicate the end of a proof, especially if it may not be immediately obvious that the proof is complete. QED stands for the Latin phrase quod erat demonstrandum, which means "That which was to be proven."