Finding the Value Using the Unit Circle Expanding Trigonometric Expressions Expanding Using Double-Angle Formulas Expanding Using Triple-Angle Formulas Expanding Using Sum/Difference Formulas Simplify Using Pythagorean Identities Simplify by Converting to Sine/Cosine Inverting Trigonometric Expressions Finding the Trig Value of an Angle Expanding Using De Moivre's Theorem