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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')).