Oscillation theorems for nonlinear second order differential equations.
Oscillation theorems for nonlinear second order differential equations.
Recently, Bobisud, Proc. Amer. Math. Soc. <bold>23</bold> (1969), 501-505, has discussed the oscillatory behavior of solutions of <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="y plus a left-parenthesis t right-parenthesis f left-parenthesis y right-parenthesis equals 0"> <mml:semantics> <mml:mrow> <mml:mi>y</mml:mi> <mml:mo>+</mml:mo> <mml:mi>a</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:mi>t</mml:mi> <mml:mo stretchy="false">)</mml:mo> <mml:mi>f</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:mi>y</mml:mi> <mml:mo stretchy="false">)</mml:mo> <mml:mo>=</mml:mo> …