On oscillation of nonlinear delay differential equations
On oscillation of nonlinear delay differential equations
Necessary, sufficient, and necessary and sufficient conditions are obtained for all solutions of the nonlinear differential equation <disp-formula content-type="math/mathml"> \[ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="StartFraction d y Over d t EndFraction plus sigma-summation Underscript j equals 1 Overscript n Endscripts q Subscript j Baseline f left-parenthesis y left-parenthesis t minus tau Subscript …