PostgreSQL/Math Functions/asin
asin(x): Returns the inverse sine of x
postgres=# -- asin(x): Returns the inverse sine of x
postgres=# SELECT asin(1), asin(0), asin(-1), asin(sin(1)) AS inverse_example;
asin | asin | asin | inverse_example
-----------------+------+------------------+-----------------
1.5707963267949 | 0 | -1.5707963267949 | 1
(1 row)
postgres=#