Pythagorean & Quotient Identities

In this lesson, we will learn about the Pythagorean Identities, the Quotient Identities, and the ranges of trigonometric functions. The Pythagorean identities tell us that sin² θ + cos² θ = 1, tan² θ + 1=sec² θ, and 1 + cot² θ = csc² θ. Additionally, the Quotient Identities tell us that sin θ / cos θ = tan θ and cos θ / sin θ = cot θ. Lastly, we will learn about the ranges of trigonometric functions. For sin θ and cos θ, the value must be from -1 to 1, for tan θ and cot θ, the value can be any real number, and for sec θ and csc θ, the value can be any real number whose absolute value is 1 or larger.