EntityQ22093344· pop 8· linked from 23 articlescisSign in to savemathematical notation for cos(x) + i sin(x)Connectionscomplex numberEntityHartley transformEntityIntelEntityFourier transformEntityexponential functionEntityRalph HartleyEntityAmerican Institute of Electrical EngineersEntitysine and cosineEntitymathematicsEntityInternational Standard Book NumberEntityQ15777EntityQ2407Entityelectric currentEntityfunctionEntityelectrical engineeringEntitycalculusEntitydigital object identifierEntityInternational Standard Serial NumberEntitytrigonometric functionEntityWilliam Rowan HamiltonEntityCategoriesMathematical identitiesTrigonometry