Sine, arcsine

sin x     sin[x]
asin x    asin[x]

Where x is a numeric, returns

sin

the sine of x, taken to be in radians. The result is between -1 and 1, or null if the argument is null or infinity.

asin

the arcsine of x; that is, the value whose sine is x. The result is in radians and lies between \(-\frac{\pi}{2}\) and \(\frac{\pi}{2}\). (The range is approximate due to rounding errors). Null is returned if the argument is not between -1 and 1.

q)sin 0.5       / sine
0.4794255
q)sin 1%0
0n

q)asin 0.8      / arcsine
0.9272952