Definition df-acos 24593

Description: Define the arccosine function. See also remarks for df-asin 24592. Since we define arccos in terms of arcsin, it shares the same branch points and cuts, namely ( -oo , -u 1 ) u. ( 1 , +oo ). (Contributed by Mario Carneiro, 31-Mar-2015.)

Assertion

Ref	Expression
df-acos	|- arccos = ( x e. CC |-> ( ( pi / 2 ) - (arcsin ` x ) ) )

Detailed syntax breakdown of Definition df-acos

Step	Hyp	Ref	Expression
1		cacos 24590	. 2 class arccos
2		vx	. . 3 setvar x
3		cc 9934	. . 3 class CC
4		cpi 14797	. . . . 5 class pi
5		c2 11070	. . . . 5 class 2
6		cdiv 10684	. . . . 5 class /
7	4, 5, 6	co 6650	. . . 4 class ( pi / 2 )
8	2	cv 1482	. . . . 5 class x
9		casin 24589	. . . . 5 class arcsin
10	8, 9	cfv 5888	. . . 4 class (arcsin ` x )
11		cmin 10266	. . . 4 class -
12	7, 10, 11	co 6650	. . 3 class ( ( pi / 2 ) - (arcsin ` x ) )
13	2, 3, 12	cmpt 4729	. 2 class ( x e. CC |-> ( ( pi / 2 ) - (arcsin ` x ) ) )
14	1, 13	wceq 1483	1 wff arccos = ( x e. CC |-> ( ( pi / 2 ) - (arcsin ` x ) ) )

This definition is referenced by:  acosf  24601  acosval  24610  dvacos  33497