The result is called derivative or slope of f at the point formula_13.
ð ə WORD_BOUNDARY ɹ ɪ z ʌ l t WORD_BOUNDARY ɪ z WORD_BOUNDARY k ɔ l d WORD_BOUNDARY d ɪ ɹ ɪ v ə t ɪ v WORD_BOUNDARY ɔ ɹ WORD_BOUNDARY s l oʊ p WORD_BOUNDARY ʌ v WORD_BOUNDARY ɛ f WORD_BOUNDARY æ t WORD_BOUNDARY ð ə WORD_BOUNDARY p ɔɪ n t WORD_BOUNDARY f ɔ ɹ m j ʊ l ə WORD_BOUNDARY θ ɜː t iː n WORD_BOUNDARY