diagonalisation vs resolving

diagonalisation and resolving both are nouns.

Word	Noun	Adjective	Verb	Adverb
diagonalisation	Yes	No	No	No
resolving	Yes	No	No	No

As nouns, resolving is a hypernym of diagonalisation; that is, resolving is a word with a broader meaning than diagonalisation:

diagonalisation: changing a square matrix to diagonal form (with all non-zero elements on the principal diagonal)
resolving: analysis into clear-cut components

Other hypernyms of diagonalisation include resolution.

diagonalisation (noun)	resolving (noun)
changing a square matrix to diagonal form (with all non-zero elements on the principal diagonal)	analysis into clear-cut components