PBL Pathways

Content Area

College Algebra, Precalculus

Time Frame

2 to 3 weeks with mini-lectures


November 29, 2009



Project Title

Arch Project


David Graser, Yavapai College, Prescott, AZ (David_Graser@yc.edu)


The two project letters below describe applications where students use the physical dimension of an arch to determine constants in the equation that models the hieght of the arch. In Project Letter 1, a catenary is used to model the St. Louis arch. In Project Letter 2, a parabola is used to model the height of the Rainbow Bridge in Arizona.

Each project can be used to explore function transformations with technology or how to solve for constants in a model equation.

Project Content

Project Letter 1 - DOC | PDF
Project Letter 2 - DOC | PDF

Scaffolding Resources



You can have the students experiment with the values of the constants on a graphing calculator. Another approach is to take the physical dimensions and substitue them into the model equation. The resulting equations can be used to solve for the unknown constants and then checked on a graphing calculator.


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