简介:Inthispaper,wesolvethequadraticp-functionalinequalities‖f(x+y)+f(x-y)-2f(x)-2f(y)‖≤‖ρ(2f((x+y)/2)+2f((x-y)/2)-f(x)-f(y))‖,(0.1)whereρisafixedcomplexnumberwith|ρ|<1,and‖2f((x+y)/2)+2f((x-y)/2)-f(x)-f(y)‖≤‖ρ(f(x+y)+f(x-y)-2f(x)-2f(y))‖,(0.2)whereρisafixedcomplexnumberwith|ρ|<1/2.Usingthedirectmethod,weprovetheHyers-Ulamstabilityofthequadraticρ-functionalinequalities(0.1)and(0.2)incomplexBanachspacesandprovetheHyers-Ulamstabilityofquadraticρ-functionalequationsassociatedwiththequadraticρ-functionalinequalities(0.1)and(0.2)incomplexBanachspaces.
简介:WeobtainseveralestimatesoftheessentialnormsoftheproductsofdifferentiationoperatorsandweightedcompositionoperatorsbetweenweightedBanachspacesofanalyticfunctionswithgeneralweights.Asapplications,wealsogiveestimatesoftheessentialnormsofweightedcompositionoperatorsbetweenweightedBanachspaceofanalyticfunctionsandBloch-typespaces.