How to prove Trigonometric Identities An identity is an equation that is known to be always true.To prove a trigonometric identity follow these suggested guidelines:1. Pick a side that is easy to transform. Pick the left-hand side (LHS) or the right-hand side (RHS)2. Use algebra or basic trigonometric identities to transform one side to another.3. If it is possible, express the entire equation in terms of one trigonometric function4. If it is possible, express the side chosen in terms of sine an