Metamath Proof Explorer


Theorem cjmulvali

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

Ref Expression
Hypothesis recl.1
|- A e. CC
Assertion cjmulvali
|- ( A x. ( * ` A ) ) = ( ( ( Re ` A ) ^ 2 ) + ( ( Im ` A ) ^ 2 ) )

Proof

Step Hyp Ref Expression
1 recl.1
 |-  A e. CC
2 cjmulval
 |-  ( A e. CC -> ( A x. ( * ` A ) ) = ( ( ( Re ` A ) ^ 2 ) + ( ( Im ` A ) ^ 2 ) ) )
3 1 2 ax-mp
 |-  ( A x. ( * ` A ) ) = ( ( ( Re ` A ) ^ 2 ) + ( ( Im ` A ) ^ 2 ) )