Koosinusfunktsioon

Koosinusfunktsioon, often denoted as cos(x), is a fundamental trigonometric function. It is one of the six standard trigonometric functions, alongside sine, tangent, cotangent, secant, and cosecant. In the context of a right-angled triangle, the cosine of an angle is defined as the ratio of the length of the adjacent side to the length of the hypotenuse.

The graph of the cosine function is a continuous wave. It oscillates between a maximum value of 1 and a minimum value of -1. The function is periodic with a period of 2π (or 360 degrees), meaning that the function's values repeat every 2π interval. The cosine function is an even function, which means that cos(-x) = cos(x) for all values of x.

The cosine function has numerous applications in various fields, including physics, engineering, signal processing, and mathematics. It is used to describe periodic phenomena such as waves, oscillations, and rotations. For instance, in physics, the cosine function is employed to model simple harmonic motion and alternating current circuits. Its ability to represent cyclical behavior makes it indispensable in analyzing and predicting phenomena that repeat over time or space.