Apple Numbers '08 - Manual (Page 209)

Chapter 12 Dictionary of Functions 209
ASIN
The ASIN function returns the arcsine (the inverse sine) of a number. While the SIN
function takes an angle and returns the sine, the ASIN function takes a sine and returns
the corresponding angle. The result is expressed in radians, in the range –pi/2 to pi/2 (–
90 to 90 degrees).
ASIN(sin)
 sin: A sine value in the range –1 through 1.
Notes
To see the resulting angle in degrees instead of radians, use the DEGREES function.
ASINH
The ASINH function calculates the inverse hyperbolic sine of a number.
ASINH(number)
 number: Any number.
ATAN
The ATAN function calculates the inverse tangent (arctangent) of a number and returns
the corresponding angle in radians, in the range –pi/2 through pi/2 (–90 through 90
degrees).
ATAN(number)
 number: A tangent value for which you want to find the corresponding angle.
Examples
AREAS(A1:F8) returns 1.
AREAS(C2:C8 B6:E6) returns 1.
AREAS((A1:F8, A10:F18)) returns 2.
AREAS((A1:C1, A3:C3, A5:C5)) returns 3.
Examples
ASIN(0.8411470984807897) returns 1, the radian measure (approximately 57.3 degrees) of the angle
that has a sine of 0.8411470984807897.
DEGREES(ASIN(0.5)) returns 30, the degree measure of the angle that has a sine of 0.5.
Examples
ASINH(27.2899171971277) returns 4.
ASINH(SINH(1)) returns 1.