The interval "(-π, π]" represents a range of real numbers that includes all values greater than negative pi (-π) and up to and including positive pi (π). In this notation, the parenthesis indicates that -π is not included in the interval, while the square bracket shows that π is included. This interval is often used in mathematics, particularly in trigonometry and calculus. This range covers approximately -3.14 to 3.14 on the number line. It is useful for defining angles in radians, where angles can be represented within this interval to avoid redundancy. For example, the angle of 0 radians is included, as well as angles like π/2 and -π/2.