Raymond B. answered 12/04/22
Math, microeconomics or criminal justice
pi/4 or 45 degrees
has the same tangent value but it's in the domain of arctan(x), while 5pi/4 is not
tan(5pi/4)= tan(pi/4) = tan(45)= tan(225)= 1 = tan(pi/4+npi) where n= any integer
but
-pi/2 < arctan(x) < pi/2, by definition or convention
otherwise you're very tempted to say falsely that arctan(tan(5pi/4)= 5pi/4