Oracle PL/SQL Tutorial/Numerical Math Functions/ACOS
ACOS(1)
<source lang="sql">
SQL> SQL> select ACOS(1) from dual;
ACOS(1)
0</source>
ACOS(-1) (2)
<source lang="sql">
SQL> select ACOS(-1) from dual;
ACOS(-1)
3.14159265</source>
<source lang="sql">
SQL> SQL> select ACOS(1) from dual;
ACOS(1)
0</source>
<source lang="sql">
SQL> select ACOS(-1) from dual;
ACOS(-1)
3.14159265</source>