The TAN function returns a tangent value of the argument. The argument x must be a radian value. The return value is a DOUBLE type.
TAN ( x )
SELECT TAN(pi()/6), TAN(pi()/3), TAN(pi()/4);
tan( pi()/6) tan( pi()/3) tan( pi()/4)
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5.773502691896257e-01 1.732050807568877e+00 9.999999999999999e-01