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 | ffvelcdmi | ⊢ ( 𝐴 ∈ ℂ → ( arccos ‘ 𝐴 ) ∈ ℂ ) |