Erat

"Quod erat demonstrandum" is a Latin expression often used in mathematics, which means "that which was to be demonstrated."

"Quod erat demonstrandum" is a Latin phrase that's often used in mathematics. It means "That which must be demonstrated."

"Quod erat demonstrandum" is a Latin expression commonly used in mathematics. It means "What was to be shown."

"Quod erat demonstrandum" is a Latin phrase common in mathematics. It means "which was to be demonstrated."