Math and Trignometric - ATAN2 Function

Description

The ATAN2 function returns the arctangent, or inverse tangent, of the specified x- and ycoordinates, in radians, between -π/2 and +π/2.

Syntax

ATAN2 (x_num, y_num)

Arguments

Notes

• A positive result represents a counterclockwise angle from the x-axis. A negative result represents a clockwise angle.

• If you want the angle returned by the ATAN2 Function to be expressed in degrees, you can convert it,

  • using the Excel Degrees Function(=DEGREES (radians))

  • or, by multiplying it by 180/PI()

• ATAN2 (a, b) equals ATAN (b/a), except that a can equal 0 in ATAN2.

• If both x_num and y_num are 0, ATAN2 returns the #DIV/0! error value.

• If either x_num or y_num is non-numeric, ATAN2 returns the #VALUE! error value.

Applicability

Excel 2007, Excel 2010, Excel 2013, Excel 2016

Example