Zero of a function
In mathematics, a zero (also sometimes called a root) of a real-, complex-, or generally vector-valued function f {\displaystyle f} , is a member x {\displaystyle x} of the domain of f {\displaystyle f} such that f ( x ) {\displaystyle f(x)} vanishes at x {\displaystyle x} ; that is, the function f {\displaystyle f} attains the value of 0 at x {\displaystyle x} , or equivalently, x {\displaystyle x} is a solution to the equation f ( x ) = 0 {\displaystyle f(x)=0} . A "zero" of a function is thus an input value that produces an output of 0.