Description: Closure for the arccos function. (Contributed by Mario Carneiro, 31-Mar-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | acoscl | ⊢ ( 𝐴 ∈ ℂ → ( arccos ‘ 𝐴 ) ∈ ℂ ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | acosf | ⊢ arccos : ℂ ⟶ ℂ | |
2 | 1 | ffvelrni | ⊢ ( 𝐴 ∈ ℂ → ( arccos ‘ 𝐴 ) ∈ ℂ ) |