EntityQ1149336· pop 17· linked from 119 articlestrigonometric seriesSign in to savesum of sines and cosines with corational frequenciesConnectionsarithmetic progressionEntityordinal numberEntitymathematicsEntityLeonhard EulerEntityInternational Standard Book NumberEntitytrigonometryEntityPythagorean theoremEntityPtolemyEntityJoseph FourierEntityBrahmaguptaEntitycalculusEntityGeorg CantorEntitydigital object identifierEntityintegralEntityseriesEntitytrigonometric functionEntityfactorialEntityHipparchusEntityG.H. HardyEntitysequenceEntityCategoriesFourier series