Apple iWork '09 - Manual (Page 331)

Chapter 12 Trigonometric Functions 331
“DEGREES” on page 334
“TAN” on page 338
“TANH” on page 339
“Listing of Trigonometric Functions” on page 326
“Value Types” on page 36
“The Elements of Formulas” on page 15
“Using the Keyboard and Mouse to Create and Edit Formulas” on page 26
“Pasting from Examples in Help” on page 41
ATAN2
The ATAN2 function returns the angle, relative to the positive x-axis, of the line passing
through the origin and the specified point.
ATAN2(x-point, y-point)
 x-point: The x-coordinate of the point the line passes through. x-point is a number
value.
 y-point: The y-coordinate of the point the line passes through. y-point is a number
value.
Usage Notes
The angle is expressed in radians, in the range –pi through +pi. To see the resulting Â
angle in degrees instead of radians, wrap this function in the DEGREES function; that
is, =DEGREES(ATAN2(x-point, y-point)).
Examples
=ATAN2(1, 1) returns 0.78539816 radians (45 degrees), the angle of a line segment from the origin to
point (1, 1).
=DEGREES(ATAN2(5, 5)) returns 45.
Related Topics
For related functions and additional information, see:
“ATAN” on page 330
“ATANH” on page 332
“DEGREES” on page 334
“TAN” on page 338