ATAN() function

SELECT ATAN( X )

SELECT ATAN(0);// Output 0
SELECT ATAN(1); // Output is 0.785398163397448
SELECT ATAN(-2); // Output is -1.10714871779409

Using ROUND() with ATAN()

SELECT ROUND(ATAN(-2),2);// Output is 1.11

ATAN() with DEGREES()

SELECT DEGREES(ATAN(0)); // Ouput is 0
SELECT DEGREES(ATAN(1)); // Output is 45 
SELECT DEGREES(ATAN(-1)); // Output is -45

SIN() function