Let a ≤ b {\displaystyle {}a\leq b} be real numbers, and let f : [ a , b ] → R {\displaystyle {}f\colon [a,b]\rightarrow \mathbb {R} } be a continuous function with f ( a ) ≤ 0 {\displaystyle {}f(a)\leq 0} and f ( b ) ≥ 0 {\displaystyle {}f(b)\geq 0} .
x ∈ [ a , b ] {\displaystyle {}x\in [a,b]} such that
![{\displaystyle {}f\colon [a,b]\rightarrow \mathbb {R} }](https://wikimedia.org/api/rest_v1/media/math/render/svg/55b2774f3530b8b9e513afa18a7fe6273a6e71f1)
![{\displaystyle {}x\in [a,b]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/fda0a4b129005203d4c9b056c7aa53a1bbbe2840)
.