Metamath Proof Explorer


Theorem cjmulvali

Description: A complex number times its conjugate. (Contributed by NM, 2-Oct-1999)

Ref Expression
Hypothesis recl.1 ⊢ A ∈ ℂ
Assertion cjmulvali ⊢ A ⁢ A ‾ = ℜ ⁡ A 2 + ℑ ⁡ A 2

Proof

Step Hyp Ref Expression
1 recl.1 ⊢ A ∈ ℂ
2 cjmulval ⊢ A ∈ ℂ → A ⁢ A ‾ = ℜ ⁡ A 2 + ℑ ⁡ A 2
3 1 2 ax-mp ⊢ A ⁢ A ‾ = ℜ ⁡ A 2 + ℑ ⁡ A 2