Metamath Proof Explorer


Definition df-sin

Description: Define the sine function. (Contributed by NM, 14-Mar-2005)

Ref Expression
Assertion df-sin
|- sin = ( x e. CC |-> ( ( ( exp ` ( _i x. x ) ) - ( exp ` ( -u _i x. x ) ) ) / ( 2 x. _i ) ) )

Detailed syntax breakdown

Step Hyp Ref Expression
0 csin
 |-  sin
1 vx
 |-  x
2 cc
 |-  CC
3 ce
 |-  exp
4 ci
 |-  _i
5 cmul
 |-  x.
6 1 cv
 |-  x
7 4 6 5 co
 |-  ( _i x. x )
8 7 3 cfv
 |-  ( exp ` ( _i x. x ) )
9 cmin
 |-  -
10 4 cneg
 |-  -u _i
11 10 6 5 co
 |-  ( -u _i x. x )
12 11 3 cfv
 |-  ( exp ` ( -u _i x. x ) )
13 8 12 9 co
 |-  ( ( exp ` ( _i x. x ) ) - ( exp ` ( -u _i x. x ) ) )
14 cdiv
 |-  /
15 c2
 |-  2
16 15 4 5 co
 |-  ( 2 x. _i )
17 13 16 14 co
 |-  ( ( ( exp ` ( _i x. x ) ) - ( exp ` ( -u _i x. x ) ) ) / ( 2 x. _i ) )
18 1 2 17 cmpt
 |-  ( x e. CC |-> ( ( ( exp ` ( _i x. x ) ) - ( exp ` ( -u _i x. x ) ) ) / ( 2 x. _i ) ) )
19 0 18 wceq
 |-  sin = ( x e. CC |-> ( ( ( exp ` ( _i x. x ) ) - ( exp ` ( -u _i x. x ) ) ) / ( 2 x. _i ) ) )