let f(x) R→R be continuous,suppose lim(x→∞）f(x)/x=0; prove 存在m∈r such that f(m)+m=0!求证明啊简便的证明啊!

let f(x) R→R be continuous,suppose lim(x→∞）f(x)/x=0; prove 存在m∈r such that f(m)+m=0!求证明啊简便的证明啊!

证明：