characteristic equation
... that mathematician Leonhard Euler discovered that a simple characteristic equation could be used to solve certain linear homogeneous differential equations?
... that mathematician <a href="./Leonhard_Euler" id="mwD38" rel="mw:WikiLink" title="Leonhard Euler">Leonhard Euler</a> discovered that a simple <b id="mwD4A"><a href="./Characteristic_equation_(calculus)" id="mwD4E" rel="mw:WikiLink" title="Characteristic equation (calculus)">characteristic equation</a></b> could be used to solve certain <a href="./Linear_differential_equation#Homogeneous_equations_with_constant_coefficients" id="mwD4I" rel="mw:WikiLink" title="Linear differential equation">linear homogeneous differential equations</a>?