This document provides instructions for using the TI-Nspire calculator to apply trigonometric addition and subtraction identities for sine and cosine functions. It outlines using the tExpand() command to expand the expressions sin(a-b), cos(a+b), and cos(a-b) and verify the trigonometric identities.

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TI-Nspire Mini-Tutorials
Trig Identities: Addition and Subtraction Identities for Sine
and Cosine (CAS)
Summary of Keystrokes
Create a calculator window:
c11
Use the tExpand() command:
A
Repeat with the following expressions:
sin(a-b)
cos(a+b)
cos(a-b)
(Make sure the variables A and B haven’t previously been defined
with other expressions.)