sel tanjo lujvo

t₂ is the angle/arctangent of tangent t₁.

Cf. sinso, tanjo, selsinso, seldutsinso.

jbovlaste

In notes:

dutsinso: x₁ is the trigonometric cosine of angle/arccosine x₂.
seldutsinso: s₂ is the angle/arccosine of cosine s₁.
selsinso: s₂ is the angle/arcsine of sine s₁.