The sum of the reciprocals of roots of an equation equals the negative coefficient of the linear term in the Maclaurin series.
Root Linear Coefficient Theorem
See also
Vieta's FormulasExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Root Linear Coefficient Theorem." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/RootLinearCoefficientTheorem.html