These are the resources that support this Virginia Standard.
T.IE.2.b - Apply the sum, difference, and half-angle identities to evaluate trigonometric function values of angles that are not integer multiples of the special angles to solve problems, including contextual situations.
In this TI Nspire tutorial for the TI-Nspire CAS, the Calculator window is used to find the trigonometric identities for addition and subtraction of sine and cosine.