Chapter 2 Solutions of Equations in One Variable
Suppose is a continuous function defined on the interval , with and of opposite sign. By the Intermediate Value Theorem, there exists in with . Although the procedure will work for the case when and have opposite signs and there is more then one root in the interval .
If , set ,
Otherwise, set ,
Then has a zero in the interval
R. L. Burden and J. D. Faires, Numerical Analysis, PWS,