Originating from the Greek analogous hóper é
dei deî
xai (ὅπερ ἔδει δεῖξαι), meaning "which had to be demonstrated". The phrase is traditionally placed in its abbreviated form (
Q.E.D.) at the end of a mathematical proof or philosophical argument. Phrase synonymous with "Quite Easily Done."
∫|Ψ(x, t)|²
dx (from -infinity to
infinity)= e^(2Γt/ħ) ∫|ψ|²dx(from -infinity to infinity)
The second term is independant of t, therefore Γ=0 & ∫|Ψ(x, t)|² dx (from -infinity to infinity)=∫|ψ|²dx(from -infinity to infinity)=1 {Normalized}
Q.E.D. "quod erat demonstrandum"