Metamath Proof Explorer


Theorem sinh-conventional

Description: Conventional definition of sinh. Here we show that the sinh definition we're using has the same meaning as the conventional definition used in some other sources. We choose a slightly different definition of sinh because it has fewer operations, and thus is more convenient to manipulate using set.mm. (Contributed by David A. Wheeler, 10-May-2015)

Ref Expression
Assertion sinh-conventional ( 𝐴 ∈ ℂ → ( sinh ‘ 𝐴 ) = ( - i · ( sin ‘ ( i · 𝐴 ) ) ) )

Proof

Step Hyp Ref Expression
1 sinhval-named ( 𝐴 ∈ ℂ → ( sinh ‘ 𝐴 ) = ( ( sin ‘ ( i · 𝐴 ) ) / i ) )
2 ax-icn i ∈ ℂ
3 mulcl ( ( i ∈ ℂ ∧ 𝐴 ∈ ℂ ) → ( i · 𝐴 ) ∈ ℂ )
4 2 3 mpan ( 𝐴 ∈ ℂ → ( i · 𝐴 ) ∈ ℂ )
5 4 sincld ( 𝐴 ∈ ℂ → ( sin ‘ ( i · 𝐴 ) ) ∈ ℂ )
6 ine0 i ≠ 0
7 divrec2 ( ( ( sin ‘ ( i · 𝐴 ) ) ∈ ℂ ∧ i ∈ ℂ ∧ i ≠ 0 ) → ( ( sin ‘ ( i · 𝐴 ) ) / i ) = ( ( 1 / i ) · ( sin ‘ ( i · 𝐴 ) ) ) )
8 2 6 7 mp3an23 ( ( sin ‘ ( i · 𝐴 ) ) ∈ ℂ → ( ( sin ‘ ( i · 𝐴 ) ) / i ) = ( ( 1 / i ) · ( sin ‘ ( i · 𝐴 ) ) ) )
9 5 8 syl ( 𝐴 ∈ ℂ → ( ( sin ‘ ( i · 𝐴 ) ) / i ) = ( ( 1 / i ) · ( sin ‘ ( i · 𝐴 ) ) ) )
10 irec ( 1 / i ) = - i
11 10 oveq1i ( ( 1 / i ) · ( sin ‘ ( i · 𝐴 ) ) ) = ( - i · ( sin ‘ ( i · 𝐴 ) ) )
12 11 a1i ( 𝐴 ∈ ℂ → ( ( 1 / i ) · ( sin ‘ ( i · 𝐴 ) ) ) = ( - i · ( sin ‘ ( i · 𝐴 ) ) ) )
13 1 9 12 3eqtrd ( 𝐴 ∈ ℂ → ( sinh ‘ 𝐴 ) = ( - i · ( sin ‘ ( i · 𝐴 ) ) ) )