ASIN
Returns the arcsine (inverse sine) of a number. The result is an angle in radians between -PI/2 and PI/2.
ASIN(number)Arguments
numberThe sine value, between -1 and 1
=ASIN(0.5)Arcsine of 0.5 = PI/6 radians (30 degrees)
=DEGREES(ASIN(0.5))Convert to degrees: arcsine of 0.5 = 30 degrees
=ASIN(1)Arcsine of 1 = PI/2 radians (90 degrees)
- •Input must be between -1 and 1
- •Returns radians, wrap in DEGREES() for degrees
- •ASIN is the inverse of SIN
- •Passing a value outside the -1 to 1 range to ASIN, which returns a #NUM! error since sine values only ever fall within that range
- •Expecting ASIN to return an answer in degrees - it always returns radians, so the result often needs to be wrapped in DEGREES to be useful
- •Confusing ASIN with SIN - ASIN takes a ratio and returns an angle, while SIN takes an angle and returns a ratio, and using the wrong one inverts the intended calculation
SINPerforms the inverse operation - takes an angle and returns a sine ratio, rather than taking a ratio and returning an angle.ACOSCalculates the inverse cosine, a related inverse trigonometric function often used alongside ASIN.DEGREESConverts ASIN's radian result into degrees, a common step since ASIN never returns degrees directly.Why does ASIN return a #NUM! error?
The input is outside the valid -1 to 1 range - sine values, and therefore valid inputs to ASIN, always fall within that range.
Does ASIN return degrees or radians?
Always radians. Wrap the result in DEGREES, like DEGREES(ASIN(0.5)), if you need degrees instead.
What's the difference between ASIN and SIN?
ASIN takes a ratio between -1 and 1 and returns the corresponding angle. SIN does the opposite - it takes an angle and returns a ratio.
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