Description: The closure of the tangent function with a complex argument. (Contributed by David A. Wheeler, 15-Mar-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | tancl | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | tanval | |
|
2 | sincl | |
|
3 | 2 | adantr | |
4 | coscl | |
|
5 | 4 | adantr | |
6 | simpr | |
|
7 | 3 5 6 | divcld | |
8 | 1 7 | eqeltrd | |