Theorem acoscl

Description: Closure for the arccos function. (Contributed by Mario Carneiro, 31-Mar-2015)

	Ref	Expression
Assertion	acoscl	$$⊢A\in ℂ\to arccos\left(A\right)\in ℂ$$

Proof

Step	Hyp	Ref	Expression
1		acosf	$$⊢arccos:ℂ⟶ℂ$$
2	1	ffvelrni	$$⊢A\in ℂ\to arccos\left(A\right)\in ℂ$$