Trigonometric Identies are used when trig functions are being used in an expression or equation. To solve trig functions one must know the identities. The identies are found using various sides of the triangle such as hypotenuse, adjacent side and oppsoite side. Its easiet to think of trig idnenties as ratios known as Sine, Cosine and Tangent. These ratios also have inverses. The inverse is just the opposite of the regular ratio. They are known as Secant, Cosecant and Cotangent. Trig Functions relate to angles in right triangles and is the ratio of two sides. The angle in trig functions is referred to as theta and reselbmles a zero with a line through the middle. Trig identies help solve trig functions and triangles by using sides and angles.