Trig functions in manual

I'm trying to use the trig functions mentioned in the postgresql manual.
Namely the cosine function listed as 

cos(float8)     float8    cosine   cos(0.4)

In both 6.5.3 and 7.0beta3 the function doesn't exist.  I get. . . 

obe-> \df cosine
result|function|arguments|description
------+--------+---------+-----------
(0 rows)

obe-> \df cos
result|function|arguments|description
------+--------+---------+-----------
(0 rows)

I didn't see any additional ./configure options to activate the math
functions, nor did I see any recent mention of this in the mail
archives.  Am I missing something?

Also FWIW the manual lists the power function as pow which also doesn't
exist as pow but as power.

obe-> \df pow 
result |function|arguments       |description               
-------+--------+----------------+--------------------------
numeric|power   |numeric numeric |m raised to the power of n
(1 row)


Thanks,
James

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James Thompson    138 Cardwell Hall  Manhattan, Ks   66506    785-532-0561 
Kansas State University                          Department of Mathematics
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