🌐EnglishEnglishDeutschEspañolFrançaisItalianoPolskiPortuguêsРусский한국어中文日本語EntityQ2621220· pop 11· linked from 173 articlesfunctional derivativeAlso known as variational derivativeconcept in calculus of variationAvailable in 11 languagesEspañolFrançaisDeutsch中文日本語РусскийItalianoCatalanUkrainian한국어Connectionsdensity functional theoryEntityphysicsEntityCategoriesCalculus of variationsDifferential calculusDifferential operatorsTopological vector spacesVariational analysis