Question: Why does Student[NumericalAnalysis][Bisection] not stop?

I was writing problems about the bisection method and decided to use the Maple routine Student[NumericalAnalysis][Bisection].  The problem I wrote generates a cubic with all three roots in a somewhat random interval.  Students are then asked to find a root to a given accuracy using the bisection method.  If one does not hit a root, the Student[NumericalAnalysis][Bisection] routine gives the desired answer.

A problem arises when the bisection algorithm generates a midpoint that is a zero of the cubic.  The standard bisection algorithm stops at this point.  When Student[NumericalAnalysis][Bisection] hits a zero, it continues on as if nothing unusual happened.  Attached is a Maple worksheet with a demonstration of this feature.

I am wondering if this behavior is appropriate since it does not follow the standard requirement of bisection that the function values at the endpoints of the interval must have opposite signs?

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