The inverse stability of functional equations is considered, i.e. when the function, approximating a solution of the equation, is an approximate solution of this equation.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-bc99-0-8, author = {Zenon Moszner}, title = {On the inverse stability of functional equations}, journal = {Banach Center Publications}, volume = {99}, year = {2013}, pages = {111-121}, zbl = {1281.39042}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-bc99-0-8} }
Zenon Moszner. On the inverse stability of functional equations. Banach Center Publications, Tome 99 (2013) pp. 111-121. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-bc99-0-8/