When angles are very small the following approximations hold:
sin(theta) ≈ theta
tan(theta) ≈ theta
(Where theta is measured in radians), so sin and tan return very nearly the same value.
2.3 degrees is 2.3*pi/180 radians → 0.0401 radians. This is small!
More precisely:
sin(2.3degrees) ≈ 0.040131792533
tan(2.3degrees) ≈ 0.040164148968