Trigonometric Identities and Special Triangles FAQ

1. Why are identities different from other equations?

Because they are true for all values of the variable.

2. Why are the so-called special angles so special?

Simply because the angles of 30°, 45° and 60° are factors of 90° and 360° and are frequently used.

3. Having used the trigonometric ratios for the special angles is it acceptable to leave roots such as √2 and √3 in the final answer to a question or problem?

Yes, it is often OK to do so unless the question specifically requests that the answer be given in a different form.i.e. to 3 significant figures.