x )/ dx , ▁the ▁( not ▁necessarily ▁constant ) ▁multip lic ative ▁factor ▁or ▁coefficient ▁of ▁the ▁differential ▁dx ▁in ▁the ▁differential ▁df ( x ). ▁▁▁ ▁A ▁coefficient ▁is ▁usually ▁a ▁constant ▁quantity , ▁but ▁the ▁differential ▁coefficient ▁of ▁f ▁is ▁a ▁constant ▁function ▁only ▁if ▁f ▁is ▁a ▁linear ▁function . ▁ ▁When ▁f ▁is ▁not ▁linear , ▁its ▁differential ▁coefficient ▁is ▁a ▁function , ▁call ▁it ▁f ′ , ▁derived ▁by ▁the ▁different iation ▁of ▁f , ▁hence , ▁the ▁modern ▁term , ▁derivative . ▁ ▁The ▁older ▁usage ▁is ▁now ▁rarely ▁seen . ▁▁ ▁Early ▁ed itions ▁of ▁Sil van us ▁P . ▁Thompson ' s ▁Calcul us ▁Made ▁E asy ▁use ▁the ▁older ▁term . ▁ ▁In ▁his ▁ 1 9 9 8 ▁update ▁of ▁this ▁text , ▁Martin ▁Gard ner ▁lets ▁the ▁first ▁use ▁of ▁" d iffer ential ▁coefficient " ▁stand , ▁along ▁with ▁Thompson ' s ▁criticism ▁of ▁the ▁term ▁as ▁a ▁need lessly ▁obsc ure ▁phrase ▁that ▁should ▁not ▁int im id ate ▁students , ▁and ▁subst it utes ▁" der iv ative " ▁for ▁the ▁remainder ▁of ▁the ▁book . ▁ ▁Category : Math emat ical ▁analysis ▁Category : D iffer ential ▁calculus ▁Category : Function s ▁and ▁ma ppings <0x0A> </s> ▁R ex ▁M und i ▁High ▁School ▁is ▁a ▁former ▁Catholic ▁high ▁school ▁in ▁Evans ville , ▁Indiana . ▁ ▁Fam ous ▁al umn i ▁include ▁Bob ▁G ri ese . ▁Its ▁name ▁comes ▁from ▁the ▁Latin ▁King ▁of ▁the