Description: Value of the sinh function at 0. (Contributed by Jon Pennant, 9-Sep-2026)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | sinh0 | ⊢ ( sinh ‘ 0 ) = 0 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 0cn | ⊢ 0 ∈ ℂ | |
| 2 | sinhval-named | ⊢ ( 0 ∈ ℂ → ( sinh ‘ 0 ) = ( ( sin ‘ ( i · 0 ) ) / i ) ) | |
| 3 | 1 2 | ax-mp | ⊢ ( sinh ‘ 0 ) = ( ( sin ‘ ( i · 0 ) ) / i ) |
| 4 | it0e0 | ⊢ ( i · 0 ) = 0 | |
| 5 | 4 | fveq2i | ⊢ ( sin ‘ ( i · 0 ) ) = ( sin ‘ 0 ) |
| 6 | sin0 | ⊢ ( sin ‘ 0 ) = 0 | |
| 7 | 5 6 | eqtri | ⊢ ( sin ‘ ( i · 0 ) ) = 0 |
| 8 | 7 | oveq1i | ⊢ ( ( sin ‘ ( i · 0 ) ) / i ) = ( 0 / i ) |
| 9 | ax-icn | ⊢ i ∈ ℂ | |
| 10 | ine0 | ⊢ i ≠ 0 | |
| 11 | 9 10 | div0i | ⊢ ( 0 / i ) = 0 |
| 12 | 3 8 11 | 3eqtri | ⊢ ( sinh ‘ 0 ) = 0 |