Dijkstra appears to have thought otherwise: "I worked at the time at the Department of Mathematics of the Eindhoven University of Technology in the Netherlands, and told at that conference that the official academic title our graduates earned was 'Mathematical Engineer', and most of the Americans began to laugh, because for them it sounded as a contradiction in terms, mathematics being sophisticated and unpractical, engineering being straightforward and practical."[1]
Before quibbling, note I said he was trained as a Mathematical Engineer, not that he had a degree in Mathematical Engineering.
"Mathematical engineering" looks like a modern invention. In any case, his undergraduate degree was in physics.