SQL Server 2005 supports 23 mathematical functions: ABS, ACOS, ASIN, ATAN, ATN2, CEILING, COS, COT, DEGREES, EXP, FLOOR, LOG, LOG10, PI, POWER, RADIANS, RAND, ROUND, SIGN, SIN, SQRT, SQUARE, and TAN. The return data types of mathematical functions are determined by two rules:

* Arithmetical functions: ABS, CEILING, DEGREES, FLOOR, POWER, RADIANS, and SIGN are returning the same data type as the input values. No implicit data type conversions are performed.

* Other mathematical functions: COS, COT, EXP, LOG, LOG10, SIN, SQRT, SQUARE and TAN are taking only FLOAT data type as input and returning FLOAT data type. Implicit data type conversion will be performed if you are calling these functions with a non-FLOAT data type.

The tutorial exercise gives you some good examples on how to use mathematical functions:

 -- ABS retuns the same data type as the input

 DECLARE @x FLOAT(53);

 DECLARE @y NUMERIC(9,2);

 DECLARE @z INT;

 SET @x = -12345.123456789E+20;

 SET @y = -12345.12;

 SET @z = -12345

 SELECT ABS(@x);

 SELECT ABS(@y);

 SELECT ABS(@z);

 GO

 1.2345123456789E+24

 12345.12

 12345