What is x-hat?

x-hat is a symbol used in mathematics to represent a unit vector in the x-direction. The symbol consists of the letter "x" with a caret symbol above it, which denotes the unit vector. A unit vector is a vector that has a magnitude (length) of 1, and is commonly used in vector calculus and physics to describe the direction of a vector. The x-hat vector is used in two-dimensional and three-dimensional coordinate systems to denote the direction of the x-axis. In physics, x-hat is often used as a basis vector in equations that involve the motion of particles along the x-axis.