Definition of quod erat demonstrandum
- “which was to be proved” (QED)
Usage examples of quod erat demonstrandum
She derived the formula from the axioms, circled the final equality, and wrote quod erat demonstrandum beneath it.
After proving every step of the geometry theorem, she wrote “quod erat demonstrandum” to show that the result had been proved.
He solved the equation, showed that both sides were equal, and concluded with “quod erat demonstrandum.”