ATAN2

Returns the arctangent of the specified x- and y- coordinates. The arctangent is the angle from the x-axis to a line containing the origin (0, 0) and a point with coordinates (x_num, y_num). The angle is given in radians between -p and p, excluding -p.

Syntax

ATAN2(x_num,y_num)

X_num   is the x-coordinate of the point.

Y_num   is the y-coordinate of the point.

Remarks

• A positive result represents a counterclockwise angle from the x-axis; a negative result represents a clockwise angle.
• 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.
• To express the arctangent in degrees, multiply the result by 180/PI( ).

Examples

ATAN2(1, 1) equals 0.785398 (p/4 radians)

ATAN2(-1, -1) equals -2.35619 (-3p/4 radians)

ATAN2(-1, -1)*180/PI() equals -135 (degrees)