Identical transformations (trigonometry)

Identical transformations in trigonometry are ways to rewrite trigonometric expressions using known identities, so that the new expression is equal to the original for all values of the variable (where both sides are defined). These transformations help simplify expressions, solve equations, or prove identities.

Important properties

• They use trigonometric identities such as the Pythagorean identity, angle sum and difference formulas, double angle and half angle formulas.

• The transformation does not change the value of the expression for any allowed value of the variable.

• They are useful for simplifying, factoring, or rewriting trigonometric expressions.