cos x

Definition

The cosine function, denoted as cos x, is a trigonometric function that represents the ratio of the adjacent side to the hypotenuse in a right triangle. It gives the value of the x-coordinate on the unit circle corresponding to a given angle.

Analogy

Imagine you are standing at point A and looking towards point B. The cosine of an angle is like measuring how much closer you are to point B compared to your starting position at point A.

Related terms

Sin x: The sine function, denoted as sin x, is another trigonometric function that represents the ratio of the opposite side to the hypotenuse in a right triangle.

Tan x: The tangent function, denoted as tan x, is yet another trigonometric function that represents the ratio of the opposite side to the adjacent side in a right triangle.

Unit Circle: A circle with a radius of 1 unit centered at the origin (0,0) on a coordinate plane. It helps visualize angles and trigonometric functions.