Share
Pin it!
Google Plus




Subscriber? Sign in to access.


 

A Direct Approach to Computing the Sine or Cosine of the Sum of Two Angles

Timothy Gutmann 

May 2003, Volume 96, Issue 5, Page 314

Abstract:
Students struggle with the formulas for computing the sines and cosines of sums of angles. My experience suggests this in part caused by the disconnect between the common, algebraic derivations of these identities and more hands-on approaches to trigonometry in which the sine and cosines functions can be experienced by students as measurements of segments within the unit circle. Here I explain a measurement-based derivation of these identities that has been helpful to my precalculus students.

Keywords:
Article
Grades 9-12
Trig Identities
Teacher
Problems
Representation