Periodicity and Parity of Trigonometric Functions
This page delves into two important properties of trigonometric functions: periodicity and parity. These properties are fundamental in understanding the behavior of trigonometric functions and are crucial for solving more complex trigonometric equations.
The concept of periodicity is introduced, defining a periodic function and providing the period for each of the main trigonometric functions.
Definition: A function f(x) is periodic with period T if f(x + T) = f(x) for all x in the domain of f.
The periods for sine, cosine, tangent, and cotangent functions are given:
- Sine and cosine have a period of 2π
- Tangent and cotangent have a period of π
The parity of trigonometric functions is also explained, distinguishing between even and odd functions.
Vocabulary: An even function is symmetric about the y-axis, while an odd function is symmetric about the origin.
The page provides the parity for each trigonometric function:
- Cosine is an even function: cos(-x) = cos(x)
- Sine, tangent, and cotangent are odd functions: sin(-x) = -sin(x), tan(-x) = -tan(x), cot(-x) = -cot(x)
These properties are essential for understanding tożsamości trygonometryczne (trigonometric identities) and solving more advanced trigonometric problems.