MySQL Tutorial/Math Numeric Functions/ATAN

ATAN(X) returns the arc tangent of X

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mysql> mysql> SELECT ATAN(2); +-----------------+ | ATAN(2) | +-----------------+ | 1.1071487177941 | +-----------------+ 1 row in set (0.02 sec) mysql> SELECT ATAN(-2); +------------------+ | ATAN(-2) | +------------------+ | -1.1071487177941 | +------------------+ 1 row in set (0.00 sec) mysql></source>

ATAN(Y,X), ATAN2(Y,X) returns the arc tangent of the two variables X and Y.

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mysql> mysql> mysql> SELECT ATAN(-2,2); +-------------------+ | ATAN(-2,2) | +-------------------+ | -0.78539816339745 | +-------------------+ 1 row in set (0.00 sec) mysql> SELECT ATAN2(PI(),0); +-----------------+ | ATAN2(PI(),0) | +-----------------+ | 1.5707963267949 | +-----------------+ 1 row in set (0.00 sec) mysql></source>