I have been following the discussion on the four required graphing calculator capabilities required for the AP Calculus examinations, and I would like to clear up any misunderstandings that may exist.
As you know, the AP Calculus course description states that a graphing calculator with the following four capabilities (either built-in or programmed) is required for the examinations: (1) to produce the graph of a function within an arbitrary viewing window (2) to find the zeros of a function (3) to compute the derivative of a function numerically (4) to compute definite integrals numerically
The capability to find the zeros of a function is equivalent to finding the point of intersection of two curves. A built in "solver" or a graphical "intersection-finder" satisfies this criterion and a student may use either without loss of credit.
As an example, consider Question 6 on the 1996 Calculus AB examination (see the May 1998, May 1999 Course Description, pages 58-59). In the solution to part (a) the student needs to find when two slopes, expressed in terms of "a", are equal. Once the equation has been setup (see bullet 4 in the "General Instructions" on page 43 of the Course Description), a solver could be used to obtain the answer (although in this case it might be easier and more accurate to solve the equation algebraically!).
I hope you find this information helpful.
Gloria Dion Assessment Division Educational Testing Service