The spelling of the word "vectrix" can be explained using IPA phonetic transcription, which is a system for representing the sounds of speech. In IPA, "vectrix" is spelled /'vɛk.trɪks/, with a stressed "e" in the first syllable and the "x" pronounced as "ks". The word is not commonly used in everyday language, but it is often seen in math and physics contexts to describe a vector quantity that has one direction and magnitude.