EntityQ1071734· pop 24· linked from 50 articlesparaxial approximationSign in to savesmall angle approximation in geometric opticsConnectionsrayEntityWolfram ResearchEntityInternational Standard Book NumberEntitylensEntityradianEntityMaxwell's equationsEntityTaylor seriesEntitygeometrical opticsEntityphysical opticsEntityWolfram AlphaEntitydimensional analysisEntityoptical axisEntityEric W. WeissteinEntityGaussian beamEntitysmall-angle approximationEntitySPIEEntityray transfer matrix analysisEntityWolfram Demonstrations ProjectEntityGaussian opticsEntityOrders of approximationEntityCategoriesGeometrical optics