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Overview - This box is used to create a rule that determines whether or not a submitted graph is correct. In general, it takes the form of testing the function, its integral, or its first or second derivative over a given set of x-values. The test can be to see if it equals, is greater than, or less than a specified value. Anywhere a number is needed, a variable can also be used. (Skip to the bottom for examples of rules.)

The figure below shows some examples of rules.

  1. Checks that the derivative at x=3 is negative.

  2. Checks that the second derivative at x=$time1 is 0.

  3. Checks that the value of the function > 7 from "Start of Graph" to x=5.

  4. Checks that the function is 0 from x=0 until the function is no longer 0, labeling this new point `notzero'.

  5. Checks that the first derivative is positive between the point `notzero' and the end of the graph.

  6. Checks to see that the value of the function at x=4 is the same as the value of the function at $time2. The Value here is &fpr_f($time2).

  7. Checks that the value of the function at point `notzero' is equal to the value of the function at x= $time3. The Value here is &fpr_f(&fpr_val(`notzero')).