EntityQ5761157· pop 6· linked from 47 articlesHilbert's nineteenth problemSign in to saveone of the 23 Hilbert problemsConnectionsJohn Forbes NashEntityderivativeEntitycalculus of variationsEntityHilbert's problemsEntityAmerican Mathematical SocietyEntityzbMATH OpenEntityInternational Standard Book NumberEntityDavid HilbertEntityBolognaEntityBaselEntitydigital object identifierEntityInternational Standard Serial NumberEntityQ180686EntityJSTOROrganizationgradientEntitybibcodeEntitymaxima and minimaEntityQ229883Entitypartial differential equationEntityLaplace's equationEntityCategoriesCalculus of variationsHilbert's problemsPartial differential equations