sel dut sinso lujvo

s₂ is the angle/arccosine of cosine s₁.

Cf. sinso, tanjo, dutsinso, selsinso, seltanjo.

jbovlaste

In notes:

dutsinso: x₁ is the trigonometric cosine of angle/arccosine x₂.
selsinso: s₂ is the angle/arcsine of sine s₁.
seltanjo: t₂ is the angle/arctangent of tangent t₁.