The arc tangent is the inverse of the tangent function. The Atn Function returns the angle &quot; Alpha &quot; , expressed in radians, using the tangent of this angle. The function can also return the angle &quot; Alpha &quot; by comparing the ratio of the length of the side that is opposite of the angle to the length of the side that is adjacent to the angle in a right-angled triangle.
反正切是正切函数的逆运算。如果将 Alpha 角的正切值作为 Atn 函数的参数执行反正切运算，则计算的结果即为 Alpha 角（以弧度为单位）。在直角三角形中，反正切函数通过 Alpha 角的对边与邻边长度之比来计算该角。