José N. Contreras
Students’ conjectures relating the midpoints of the sides of a quadrilateral are inspired by using The Geometer’s Sketchpad and justified by proofs.
Angeline K. Gaddy, Shannon E. Harmon, Angela T. Barlow, Charles D. Milligan, and Rongjin Huang
A classroom vignette illustrates the design principles of focus, coherence, and rigor that frame the Common Core State Standards for Mathematics.
Azael Barrera
A method to determine all the inverse trigonometric functions directly from the unit circle.
Yun Lu, Francis J. Vasko, Trevor J. Drummond, and Lisa E. Vasko
Events that seem more representative may be judged more probable, so experiments and proof are needed to help students analyze a mathematical outcome.
Yajun Yang and Sheldon P. Gordon
Two methods for precalculus students to find exact-fit polynomials.