ASIN()

Syntax. ASIN(number)

Definition. Use the ASIN() function to calculate the adjacent angle based on the sine (see Figure 16-5).

Argument

• number (required) The sine of the angle; must be between –1 and 1

Background. This function calculates the angle from a sine value. The result is a radian measure and has to be converted into degrees with the DEGREES() function or by multiplying the result by 180/PI().

Because each angle occurs two times in a full circle, the value range for the arcsine is restricted.

• If the angle is calculated as a radian measure, the value range spans –π/2 to π/2.

• If the angle is calculated in degrees, the value range spans –90° to 90°.

The values of the arcsine in a coordinate plane look like this:

Figure 16-5. The ASIN() function.

Example. The ASIN() function is used to calculate the angles of a right triangle based on the opposite leg and the hypotenuse.

More examples for this function are:

• =ASIN(1) returns the radian measure 1.570796327 and a 90º angle.

• =ASIN(0.5) returns the radian measure 0.523598776 and a 150º angle.

• =ASIN(-0.5) returns the radian measure -0.523598776 and a 210º angle.

See Also

ASINH(), PI(), SIN()

Sample Files

Use the SIN_COS worksheet in the Chapter16.xls or Chapter16.xlsx sample file. The sample files are found in the Chapter16 folder. For more information about the sample files, see the section titled Using the Sample Files.