FiniteField.unit_isSquare_iff

∀ {F : Type u_3} [inst : Field F] [inst_1 : Fintype F],
  ringChar F ≠ 2 → ∀ (a : Fˣ), IsSquare a ↔ a ^ (Fintype.card F / 2) = 1

A unit a of a finite field F of odd characteristic is a square if and only if a ^ (#F / 2) = 1.

Defined in: Mathlib.FieldTheory.Finite.Basic
Cited by: 2 results in Mathlib
Foundations: Depth 139 from the axioms · uses propext, Classical.choice, Quot.sound
Assumes: Field Fintype

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