| Step | Hyp | Ref
| Expression |
| 1 | | df-tan 14802 |
. . . 4
⊢ tan =
(𝑥 ∈ (◡cos “ (ℂ ∖ {0})) ↦
((sin‘𝑥) /
(cos‘𝑥))) |
| 2 | | cnvimass 5485 |
. . . . . . . . 9
⊢ (◡cos “ (ℂ ∖ {0})) ⊆
dom cos |
| 3 | | cosf 14855 |
. . . . . . . . . 10
⊢
cos:ℂ⟶ℂ |
| 4 | 3 | fdmi 6052 |
. . . . . . . . 9
⊢ dom cos =
ℂ |
| 5 | 2, 4 | sseqtri 3637 |
. . . . . . . 8
⊢ (◡cos “ (ℂ ∖ {0})) ⊆
ℂ |
| 6 | 5 | sseli 3599 |
. . . . . . 7
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
𝑥 ∈
ℂ) |
| 7 | 6 | sincld 14860 |
. . . . . 6
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
(sin‘𝑥) ∈
ℂ) |
| 8 | 6 | coscld 14861 |
. . . . . 6
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
(cos‘𝑥) ∈
ℂ) |
| 9 | | ffn 6045 |
. . . . . . . 8
⊢
(cos:ℂ⟶ℂ → cos Fn ℂ) |
| 10 | | elpreima 6337 |
. . . . . . . 8
⊢ (cos Fn
ℂ → (𝑥 ∈
(◡cos “ (ℂ ∖ {0}))
↔ (𝑥 ∈ ℂ
∧ (cos‘𝑥) ∈
(ℂ ∖ {0})))) |
| 11 | 3, 9, 10 | mp2b 10 |
. . . . . . 7
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) ↔
(𝑥 ∈ ℂ ∧
(cos‘𝑥) ∈
(ℂ ∖ {0}))) |
| 12 | | eldifsni 4320 |
. . . . . . . 8
⊢
((cos‘𝑥)
∈ (ℂ ∖ {0}) → (cos‘𝑥) ≠ 0) |
| 13 | 12 | adantl 482 |
. . . . . . 7
⊢ ((𝑥 ∈ ℂ ∧
(cos‘𝑥) ∈
(ℂ ∖ {0})) → (cos‘𝑥) ≠ 0) |
| 14 | 11, 13 | sylbi 207 |
. . . . . 6
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
(cos‘𝑥) ≠
0) |
| 15 | 7, 8, 14 | divrecd 10804 |
. . . . 5
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
((sin‘𝑥) /
(cos‘𝑥)) =
((sin‘𝑥) · (1
/ (cos‘𝑥)))) |
| 16 | 15 | mpteq2ia 4740 |
. . . 4
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) ↦
((sin‘𝑥) /
(cos‘𝑥))) = (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) ↦
((sin‘𝑥) · (1
/ (cos‘𝑥)))) |
| 17 | 1, 16 | eqtri 2644 |
. . 3
⊢ tan =
(𝑥 ∈ (◡cos “ (ℂ ∖ {0})) ↦
((sin‘𝑥) · (1
/ (cos‘𝑥)))) |
| 18 | 17 | oveq2i 6661 |
. 2
⊢ (ℂ
D tan) = (ℂ D (𝑥
∈ (◡cos “ (ℂ ∖
{0})) ↦ ((sin‘𝑥) · (1 / (cos‘𝑥))))) |
| 19 | | cnelprrecn 10029 |
. . . . 5
⊢ ℂ
∈ {ℝ, ℂ} |
| 20 | 19 | a1i 11 |
. . . 4
⊢ (⊤
→ ℂ ∈ {ℝ, ℂ}) |
| 21 | | difss 3737 |
. . . . . . . . 9
⊢ (ℂ
∖ {0}) ⊆ ℂ |
| 22 | | imass2 5501 |
. . . . . . . . 9
⊢ ((ℂ
∖ {0}) ⊆ ℂ → (◡cos “ (ℂ ∖ {0})) ⊆
(◡cos “
ℂ)) |
| 23 | 21, 22 | ax-mp 5 |
. . . . . . . 8
⊢ (◡cos “ (ℂ ∖ {0})) ⊆
(◡cos “ ℂ) |
| 24 | | fimacnv 6347 |
. . . . . . . . 9
⊢
(cos:ℂ⟶ℂ → (◡cos “ ℂ) =
ℂ) |
| 25 | 3, 24 | ax-mp 5 |
. . . . . . . 8
⊢ (◡cos “ ℂ) =
ℂ |
| 26 | 23, 25 | sseqtri 3637 |
. . . . . . 7
⊢ (◡cos “ (ℂ ∖ {0})) ⊆
ℂ |
| 27 | 26 | sseli 3599 |
. . . . . 6
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
𝑥 ∈
ℂ) |
| 28 | 27 | sincld 14860 |
. . . . 5
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
(sin‘𝑥) ∈
ℂ) |
| 29 | 28 | adantl 482 |
. . . 4
⊢
((⊤ ∧ 𝑥
∈ (◡cos “ (ℂ ∖
{0}))) → (sin‘𝑥)
∈ ℂ) |
| 30 | 8 | adantl 482 |
. . . 4
⊢
((⊤ ∧ 𝑥
∈ (◡cos “ (ℂ ∖
{0}))) → (cos‘𝑥)
∈ ℂ) |
| 31 | | sincl 14856 |
. . . . . 6
⊢ (𝑥 ∈ ℂ →
(sin‘𝑥) ∈
ℂ) |
| 32 | 31 | adantl 482 |
. . . . 5
⊢
((⊤ ∧ 𝑥
∈ ℂ) → (sin‘𝑥) ∈ ℂ) |
| 33 | | coscl 14857 |
. . . . . 6
⊢ (𝑥 ∈ ℂ →
(cos‘𝑥) ∈
ℂ) |
| 34 | 33 | adantl 482 |
. . . . 5
⊢
((⊤ ∧ 𝑥
∈ ℂ) → (cos‘𝑥) ∈ ℂ) |
| 35 | | dvsin 23745 |
. . . . . 6
⊢ (ℂ
D sin) = cos |
| 36 | | sinf 14854 |
. . . . . . . . 9
⊢
sin:ℂ⟶ℂ |
| 37 | 36 | a1i 11 |
. . . . . . . 8
⊢ (⊤
→ sin:ℂ⟶ℂ) |
| 38 | 37 | feqmptd 6249 |
. . . . . . 7
⊢ (⊤
→ sin = (𝑥 ∈
ℂ ↦ (sin‘𝑥))) |
| 39 | 38 | oveq2d 6666 |
. . . . . 6
⊢ (⊤
→ (ℂ D sin) = (ℂ D (𝑥 ∈ ℂ ↦ (sin‘𝑥)))) |
| 40 | 3 | a1i 11 |
. . . . . . 7
⊢ (⊤
→ cos:ℂ⟶ℂ) |
| 41 | 40 | feqmptd 6249 |
. . . . . 6
⊢ (⊤
→ cos = (𝑥 ∈
ℂ ↦ (cos‘𝑥))) |
| 42 | 35, 39, 41 | 3eqtr3a 2680 |
. . . . 5
⊢ (⊤
→ (ℂ D (𝑥 ∈
ℂ ↦ (sin‘𝑥))) = (𝑥 ∈ ℂ ↦ (cos‘𝑥))) |
| 43 | 26 | a1i 11 |
. . . . 5
⊢ (⊤
→ (◡cos “ (ℂ ∖
{0})) ⊆ ℂ) |
| 44 | | eqid 2622 |
. . . . . . . 8
⊢
(TopOpen‘ℂfld) =
(TopOpen‘ℂfld) |
| 45 | 44 | cnfldtopon 22586 |
. . . . . . 7
⊢
(TopOpen‘ℂfld) ∈
(TopOn‘ℂ) |
| 46 | 45 | toponunii 20721 |
. . . . . . . 8
⊢ ℂ =
∪
(TopOpen‘ℂfld) |
| 47 | 46 | restid 16094 |
. . . . . . 7
⊢
((TopOpen‘ℂfld) ∈ (TopOn‘ℂ)
→ ((TopOpen‘ℂfld) ↾t ℂ) =
(TopOpen‘ℂfld)) |
| 48 | 45, 47 | ax-mp 5 |
. . . . . 6
⊢
((TopOpen‘ℂfld) ↾t ℂ) =
(TopOpen‘ℂfld) |
| 49 | 48 | eqcomi 2631 |
. . . . 5
⊢
(TopOpen‘ℂfld) =
((TopOpen‘ℂfld) ↾t
ℂ) |
| 50 | | dvtanlem 33459 |
. . . . . 6
⊢ (◡cos “ (ℂ ∖ {0})) ∈
(TopOpen‘ℂfld) |
| 51 | 50 | a1i 11 |
. . . . 5
⊢ (⊤
→ (◡cos “ (ℂ ∖
{0})) ∈ (TopOpen‘ℂfld)) |
| 52 | 20, 32, 34, 42, 43, 49, 44, 51 | dvmptres 23726 |
. . . 4
⊢ (⊤
→ (ℂ D (𝑥 ∈
(◡cos “ (ℂ ∖ {0}))
↦ (sin‘𝑥))) =
(𝑥 ∈ (◡cos “ (ℂ ∖ {0})) ↦
(cos‘𝑥))) |
| 53 | 8, 14 | reccld 10794 |
. . . . 5
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) → (1
/ (cos‘𝑥)) ∈
ℂ) |
| 54 | 53 | adantl 482 |
. . . 4
⊢
((⊤ ∧ 𝑥
∈ (◡cos “ (ℂ ∖
{0}))) → (1 / (cos‘𝑥)) ∈ ℂ) |
| 55 | | ovexd 6680 |
. . . 4
⊢
((⊤ ∧ 𝑥
∈ (◡cos “ (ℂ ∖
{0}))) → (-(1 / ((cos‘𝑥)↑2)) · -(sin‘𝑥)) ∈ V) |
| 56 | 11 | simprbi 480 |
. . . . . 6
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
(cos‘𝑥) ∈
(ℂ ∖ {0})) |
| 57 | 56 | adantl 482 |
. . . . 5
⊢
((⊤ ∧ 𝑥
∈ (◡cos “ (ℂ ∖
{0}))) → (cos‘𝑥)
∈ (ℂ ∖ {0})) |
| 58 | 29 | negcld 10379 |
. . . . 5
⊢
((⊤ ∧ 𝑥
∈ (◡cos “ (ℂ ∖
{0}))) → -(sin‘𝑥) ∈ ℂ) |
| 59 | | eldifi 3732 |
. . . . . . 7
⊢ (𝑦 ∈ (ℂ ∖ {0})
→ 𝑦 ∈
ℂ) |
| 60 | | eldifsni 4320 |
. . . . . . 7
⊢ (𝑦 ∈ (ℂ ∖ {0})
→ 𝑦 ≠
0) |
| 61 | 59, 60 | reccld 10794 |
. . . . . 6
⊢ (𝑦 ∈ (ℂ ∖ {0})
→ (1 / 𝑦) ∈
ℂ) |
| 62 | 61 | adantl 482 |
. . . . 5
⊢
((⊤ ∧ 𝑦
∈ (ℂ ∖ {0})) → (1 / 𝑦) ∈ ℂ) |
| 63 | | negex 10279 |
. . . . . 6
⊢ -(1 /
(𝑦↑2)) ∈
V |
| 64 | 63 | a1i 11 |
. . . . 5
⊢
((⊤ ∧ 𝑦
∈ (ℂ ∖ {0})) → -(1 / (𝑦↑2)) ∈ V) |
| 65 | 32 | negcld 10379 |
. . . . . 6
⊢
((⊤ ∧ 𝑥
∈ ℂ) → -(sin‘𝑥) ∈ ℂ) |
| 66 | | dvcos 23746 |
. . . . . . 7
⊢ (ℂ
D cos) = (𝑥 ∈ ℂ
↦ -(sin‘𝑥)) |
| 67 | 41 | oveq2d 6666 |
. . . . . . 7
⊢ (⊤
→ (ℂ D cos) = (ℂ D (𝑥 ∈ ℂ ↦ (cos‘𝑥)))) |
| 68 | 66, 67 | syl5reqr 2671 |
. . . . . 6
⊢ (⊤
→ (ℂ D (𝑥 ∈
ℂ ↦ (cos‘𝑥))) = (𝑥 ∈ ℂ ↦ -(sin‘𝑥))) |
| 69 | 20, 34, 65, 68, 43, 49, 44, 51 | dvmptres 23726 |
. . . . 5
⊢ (⊤
→ (ℂ D (𝑥 ∈
(◡cos “ (ℂ ∖ {0}))
↦ (cos‘𝑥))) =
(𝑥 ∈ (◡cos “ (ℂ ∖ {0})) ↦
-(sin‘𝑥))) |
| 70 | | ax-1cn 9994 |
. . . . . 6
⊢ 1 ∈
ℂ |
| 71 | | dvrec 23718 |
. . . . . 6
⊢ (1 ∈
ℂ → (ℂ D (𝑦 ∈ (ℂ ∖ {0}) ↦ (1 /
𝑦))) = (𝑦 ∈ (ℂ ∖ {0}) ↦ -(1 /
(𝑦↑2)))) |
| 72 | 70, 71 | mp1i 13 |
. . . . 5
⊢ (⊤
→ (ℂ D (𝑦 ∈
(ℂ ∖ {0}) ↦ (1 / 𝑦))) = (𝑦 ∈ (ℂ ∖ {0}) ↦ -(1 /
(𝑦↑2)))) |
| 73 | | oveq2 6658 |
. . . . 5
⊢ (𝑦 = (cos‘𝑥) → (1 / 𝑦) = (1 / (cos‘𝑥))) |
| 74 | | oveq1 6657 |
. . . . . . 7
⊢ (𝑦 = (cos‘𝑥) → (𝑦↑2) = ((cos‘𝑥)↑2)) |
| 75 | 74 | oveq2d 6666 |
. . . . . 6
⊢ (𝑦 = (cos‘𝑥) → (1 / (𝑦↑2)) = (1 / ((cos‘𝑥)↑2))) |
| 76 | 75 | negeqd 10275 |
. . . . 5
⊢ (𝑦 = (cos‘𝑥) → -(1 / (𝑦↑2)) = -(1 / ((cos‘𝑥)↑2))) |
| 77 | 20, 20, 57, 58, 62, 64, 69, 72, 73, 76 | dvmptco 23735 |
. . . 4
⊢ (⊤
→ (ℂ D (𝑥 ∈
(◡cos “ (ℂ ∖ {0}))
↦ (1 / (cos‘𝑥)))) = (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) ↦
(-(1 / ((cos‘𝑥)↑2)) · -(sin‘𝑥)))) |
| 78 | 20, 29, 30, 52, 54, 55, 77 | dvmptmul 23724 |
. . 3
⊢ (⊤
→ (ℂ D (𝑥 ∈
(◡cos “ (ℂ ∖ {0}))
↦ ((sin‘𝑥)
· (1 / (cos‘𝑥))))) = (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) ↦
(((cos‘𝑥) · (1
/ (cos‘𝑥))) + ((-(1 /
((cos‘𝑥)↑2))
· -(sin‘𝑥))
· (sin‘𝑥))))) |
| 79 | 78 | trud 1493 |
. 2
⊢ (ℂ
D (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) ↦
((sin‘𝑥) · (1
/ (cos‘𝑥))))) =
(𝑥 ∈ (◡cos “ (ℂ ∖ {0})) ↦
(((cos‘𝑥) · (1
/ (cos‘𝑥))) + ((-(1 /
((cos‘𝑥)↑2))
· -(sin‘𝑥))
· (sin‘𝑥)))) |
| 80 | | ovex 6678 |
. . . . 5
⊢
((sin‘𝑥) /
(cos‘𝑥)) ∈
V |
| 81 | 80, 1 | dmmpti 6023 |
. . . 4
⊢ dom tan =
(◡cos “ (ℂ ∖
{0})) |
| 82 | 81 | eqcomi 2631 |
. . 3
⊢ (◡cos “ (ℂ ∖ {0})) = dom
tan |
| 83 | 8 | sqcld 13006 |
. . . . . . 7
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
((cos‘𝑥)↑2)
∈ ℂ) |
| 84 | 7 | sqcld 13006 |
. . . . . . 7
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
((sin‘𝑥)↑2)
∈ ℂ) |
| 85 | | sqne0 12930 |
. . . . . . . . 9
⊢
((cos‘𝑥)
∈ ℂ → (((cos‘𝑥)↑2) ≠ 0 ↔ (cos‘𝑥) ≠ 0)) |
| 86 | 8, 85 | syl 17 |
. . . . . . . 8
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
(((cos‘𝑥)↑2)
≠ 0 ↔ (cos‘𝑥)
≠ 0)) |
| 87 | 14, 86 | mpbird 247 |
. . . . . . 7
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
((cos‘𝑥)↑2) ≠
0) |
| 88 | 83, 84, 83, 87 | divdird 10839 |
. . . . . 6
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
((((cos‘𝑥)↑2) +
((sin‘𝑥)↑2)) /
((cos‘𝑥)↑2)) =
((((cos‘𝑥)↑2) /
((cos‘𝑥)↑2)) +
(((sin‘𝑥)↑2) /
((cos‘𝑥)↑2)))) |
| 89 | 83, 84 | addcomd 10238 |
. . . . . . . 8
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
(((cos‘𝑥)↑2) +
((sin‘𝑥)↑2)) =
(((sin‘𝑥)↑2) +
((cos‘𝑥)↑2))) |
| 90 | | sincossq 14906 |
. . . . . . . . 9
⊢ (𝑥 ∈ ℂ →
(((sin‘𝑥)↑2) +
((cos‘𝑥)↑2)) =
1) |
| 91 | 6, 90 | syl 17 |
. . . . . . . 8
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
(((sin‘𝑥)↑2) +
((cos‘𝑥)↑2)) =
1) |
| 92 | 89, 91 | eqtrd 2656 |
. . . . . . 7
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
(((cos‘𝑥)↑2) +
((sin‘𝑥)↑2)) =
1) |
| 93 | 92 | oveq1d 6665 |
. . . . . 6
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
((((cos‘𝑥)↑2) +
((sin‘𝑥)↑2)) /
((cos‘𝑥)↑2)) =
(1 / ((cos‘𝑥)↑2))) |
| 94 | 88, 93 | eqtr3d 2658 |
. . . . 5
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
((((cos‘𝑥)↑2) /
((cos‘𝑥)↑2)) +
(((sin‘𝑥)↑2) /
((cos‘𝑥)↑2))) =
(1 / ((cos‘𝑥)↑2))) |
| 95 | 8, 14 | recidd 10796 |
. . . . . . 7
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
((cos‘𝑥) · (1
/ (cos‘𝑥))) =
1) |
| 96 | 83, 87 | dividd 10799 |
. . . . . . 7
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
(((cos‘𝑥)↑2) /
((cos‘𝑥)↑2)) =
1) |
| 97 | 95, 96 | eqtr4d 2659 |
. . . . . 6
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
((cos‘𝑥) · (1
/ (cos‘𝑥))) =
(((cos‘𝑥)↑2) /
((cos‘𝑥)↑2))) |
| 98 | 7, 7, 83, 87 | div23d 10838 |
. . . . . . 7
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
(((sin‘𝑥) ·
(sin‘𝑥)) /
((cos‘𝑥)↑2)) =
(((sin‘𝑥) /
((cos‘𝑥)↑2))
· (sin‘𝑥))) |
| 99 | 7 | sqvald 13005 |
. . . . . . . 8
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
((sin‘𝑥)↑2) =
((sin‘𝑥) ·
(sin‘𝑥))) |
| 100 | 99 | oveq1d 6665 |
. . . . . . 7
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
(((sin‘𝑥)↑2) /
((cos‘𝑥)↑2)) =
(((sin‘𝑥) ·
(sin‘𝑥)) /
((cos‘𝑥)↑2))) |
| 101 | 83, 87 | reccld 10794 |
. . . . . . . . . 10
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) → (1
/ ((cos‘𝑥)↑2))
∈ ℂ) |
| 102 | 101, 7 | mul2negd 10485 |
. . . . . . . . 9
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
(-(1 / ((cos‘𝑥)↑2)) · -(sin‘𝑥)) = ((1 / ((cos‘𝑥)↑2)) ·
(sin‘𝑥))) |
| 103 | 7, 83, 87 | divrec2d 10805 |
. . . . . . . . 9
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
((sin‘𝑥) /
((cos‘𝑥)↑2)) =
((1 / ((cos‘𝑥)↑2)) · (sin‘𝑥))) |
| 104 | 102, 103 | eqtr4d 2659 |
. . . . . . . 8
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
(-(1 / ((cos‘𝑥)↑2)) · -(sin‘𝑥)) = ((sin‘𝑥) / ((cos‘𝑥)↑2))) |
| 105 | 104 | oveq1d 6665 |
. . . . . . 7
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
((-(1 / ((cos‘𝑥)↑2)) · -(sin‘𝑥)) · (sin‘𝑥)) = (((sin‘𝑥) / ((cos‘𝑥)↑2)) ·
(sin‘𝑥))) |
| 106 | 98, 100, 105 | 3eqtr4rd 2667 |
. . . . . 6
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
((-(1 / ((cos‘𝑥)↑2)) · -(sin‘𝑥)) · (sin‘𝑥)) = (((sin‘𝑥)↑2) / ((cos‘𝑥)↑2))) |
| 107 | 97, 106 | oveq12d 6668 |
. . . . 5
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
(((cos‘𝑥) · (1
/ (cos‘𝑥))) + ((-(1 /
((cos‘𝑥)↑2))
· -(sin‘𝑥))
· (sin‘𝑥))) =
((((cos‘𝑥)↑2) /
((cos‘𝑥)↑2)) +
(((sin‘𝑥)↑2) /
((cos‘𝑥)↑2)))) |
| 108 | | 2nn0 11309 |
. . . . . 6
⊢ 2 ∈
ℕ0 |
| 109 | | expneg 12868 |
. . . . . 6
⊢
(((cos‘𝑥)
∈ ℂ ∧ 2 ∈ ℕ0) → ((cos‘𝑥)↑-2) = (1 /
((cos‘𝑥)↑2))) |
| 110 | 8, 108, 109 | sylancl 694 |
. . . . 5
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
((cos‘𝑥)↑-2) =
(1 / ((cos‘𝑥)↑2))) |
| 111 | 94, 107, 110 | 3eqtr4d 2666 |
. . . 4
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) →
(((cos‘𝑥) · (1
/ (cos‘𝑥))) + ((-(1 /
((cos‘𝑥)↑2))
· -(sin‘𝑥))
· (sin‘𝑥))) =
((cos‘𝑥)↑-2)) |
| 112 | 111 | rgen 2922 |
. . 3
⊢
∀𝑥 ∈
(◡cos “ (ℂ ∖
{0}))(((cos‘𝑥)
· (1 / (cos‘𝑥))) + ((-(1 / ((cos‘𝑥)↑2)) · -(sin‘𝑥)) · (sin‘𝑥))) = ((cos‘𝑥)↑-2) |
| 113 | | mpteq12 4736 |
. . 3
⊢ (((◡cos “ (ℂ ∖ {0})) = dom tan
∧ ∀𝑥 ∈
(◡cos “ (ℂ ∖
{0}))(((cos‘𝑥)
· (1 / (cos‘𝑥))) + ((-(1 / ((cos‘𝑥)↑2)) · -(sin‘𝑥)) · (sin‘𝑥))) = ((cos‘𝑥)↑-2)) → (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) ↦
(((cos‘𝑥) · (1
/ (cos‘𝑥))) + ((-(1 /
((cos‘𝑥)↑2))
· -(sin‘𝑥))
· (sin‘𝑥)))) =
(𝑥 ∈ dom tan ↦
((cos‘𝑥)↑-2))) |
| 114 | 82, 112, 113 | mp2an 708 |
. 2
⊢ (𝑥 ∈ (◡cos “ (ℂ ∖ {0})) ↦
(((cos‘𝑥) · (1
/ (cos‘𝑥))) + ((-(1 /
((cos‘𝑥)↑2))
· -(sin‘𝑥))
· (sin‘𝑥)))) =
(𝑥 ∈ dom tan ↦
((cos‘𝑥)↑-2)) |
| 115 | 18, 79, 114 | 3eqtri 2648 |
1
⊢ (ℂ
D tan) = (𝑥 ∈ dom tan
↦ ((cos‘𝑥)↑-2)) |