222 Appendix D: A Detailed Look at _

The function's graph is either convex everywhere or concave everywhere.

The only local minima and maxima of the function's graph occur singly between adjacent zeros of the function.

In addition, it is assumed that the _algorithm will not be interrupted by an improper operation.

Accuracy of the Root

When you use the _ key to find a root of an equation, the root is found accurately. The displayed root either gives a calculated function value (f(x)) exactly equal to zero or else is a 10-digit number virtually adjacent to the place where the function's graph crosses the x-axis. Any such root has an accuracy within two or three units in the 10th significant digit.

In most situations the calculated root is an accurate estimate of the theoretical (infinitely precise) root of the equation. However, certain conditions can cause the finite accuracy of the calculator to give a result that appears to be inconsistent with your theoretical expectation.