%0 Journal Article %T Using Rolle's Theorem in Exponential Function-Derivative Approximation %J Canadian mathematical bulletin %D 1975 %P 755-757 %V 18 %N 5 %U http://geodesic.mathdoc.fr/articles/10.4153/CMB-1975-131-5/ %R 10.4153/CMB-1975-131-5 %F 10_4153_CMB_1975_131_5