One of my students once told me that his brother, an engineer, said that gradients were used in some engineering fields.
Thanks for the ideas for construction projects for the volumes by cross sections. I plan to use them this year.
Also, re the question about grading AP exams and whether or not the intersect button is ok to use. It is (as long as you explain why you are doing it), but some students lost points because they used the trace button, which was not as accurate.
Judith Kritzberg Mathematics Department, The Latin School of Chicago