Metamath Proof Explorer


Theorem absval2i

Description: Value of absolute value function. Definition 10.36 of Gleason p. 133. (Contributed by NM, 2-Oct-1999)

Ref Expression
Hypothesis absvalsqi.1
|- A e. CC
Assertion absval2i
|- ( abs ` A ) = ( sqrt ` ( ( ( Re ` A ) ^ 2 ) + ( ( Im ` A ) ^ 2 ) ) )

Proof

Step Hyp Ref Expression
1 absvalsqi.1
 |-  A e. CC
2 absval2
 |-  ( A e. CC -> ( abs ` A ) = ( sqrt ` ( ( ( Re ` A ) ^ 2 ) + ( ( Im ` A ) ^ 2 ) ) ) )
3 1 2 ax-mp
 |-  ( abs ` A ) = ( sqrt ` ( ( ( Re ` A ) ^ 2 ) + ( ( Im ` A ) ^ 2 ) ) )