Related Functions:

The ASIN function Returns the arcsine, or inverse sine, of a number. The arcsine is the angle whose sine is number. The returned angle is given in radians in the range -\pi/2 to \pi/2.

Syntax

=ASIN(number)

Arguments

Argument Description
number The sine of the angle you want and must be from -1 to 1

Examples

  A B C
1 Formula Result Notes
2 =ASIN(-0.5) -0.523598776 Arcsine of -0.5 in radians, –\pi/6
3 =ASIN(-0.5)*180/PI() -30 Arcsine of -0.5 in degrees
4 =ASIN(1/SQRT(2)) 0.785398163 Arcsine of 1/ \sqrt{2} in radians
5 =DEGREES(ASIN(1/SQRT(2))) 45 Arcsine of 1/ \sqrt{2} in degrees

Note: If you want the angle returned by the ASIN function to be expressed in degrees, you can convert it, using the DEGREES function: =DEGREES(radians)

Common Function Error(s)

Problem What went wrong
#VALUE! Occurs if the supplied number argument is not recognized as a numeric value
#NUM! Occurs if the supplied number argument is not in the range -1 to +1

trigonometry_triangleThe arcsine is the inverse of sine. Therefore, for the simple right-angle triangle at right, the arcsine of the opposite side (a), divided by the hypotenuse (h), is equal to angle A, i.e. for the triangle at right, the arcsine for angle B is calculated as:  

    \[    A = arcsin \left( \frac{a}h \right)    \]

See Wikipedia for more information on Inverse Trigonometric Functions.