Proof of Theorem dcubic2
| Step | Hyp | Ref
| Expression |
| 1 | | dcubic2.u |
. . . . 5
⊢ (𝜑 → 𝑈 ∈ ℂ) |
| 2 | | dcubic.t |
. . . . 5
⊢ (𝜑 → 𝑇 ∈ ℂ) |
| 3 | | dcubic.0 |
. . . . 5
⊢ (𝜑 → 𝑇 ≠ 0) |
| 4 | 1, 2, 3 | divcld 10801 |
. . . 4
⊢ (𝜑 → (𝑈 / 𝑇) ∈ ℂ) |
| 5 | 4 | adantr 481 |
. . 3
⊢ ((𝜑 ∧ (𝑈↑3) = (𝐺 − 𝑁)) → (𝑈 / 𝑇) ∈ ℂ) |
| 6 | | 3nn0 11310 |
. . . . . . 7
⊢ 3 ∈
ℕ0 |
| 7 | 6 | a1i 11 |
. . . . . 6
⊢ (𝜑 → 3 ∈
ℕ0) |
| 8 | 1, 2, 3, 7 | expdivd 13022 |
. . . . 5
⊢ (𝜑 → ((𝑈 / 𝑇)↑3) = ((𝑈↑3) / (𝑇↑3))) |
| 9 | 8 | adantr 481 |
. . . 4
⊢ ((𝜑 ∧ (𝑈↑3) = (𝐺 − 𝑁)) → ((𝑈 / 𝑇)↑3) = ((𝑈↑3) / (𝑇↑3))) |
| 10 | | oveq1 6657 |
. . . . 5
⊢ ((𝑈↑3) = (𝐺 − 𝑁) → ((𝑈↑3) / (𝑇↑3)) = ((𝐺 − 𝑁) / (𝑇↑3))) |
| 11 | | dcubic.3 |
. . . . . . 7
⊢ (𝜑 → (𝑇↑3) = (𝐺 − 𝑁)) |
| 12 | 11 | oveq1d 6665 |
. . . . . 6
⊢ (𝜑 → ((𝑇↑3) / (𝑇↑3)) = ((𝐺 − 𝑁) / (𝑇↑3))) |
| 13 | | expcl 12878 |
. . . . . . . 8
⊢ ((𝑇 ∈ ℂ ∧ 3 ∈
ℕ0) → (𝑇↑3) ∈ ℂ) |
| 14 | 2, 6, 13 | sylancl 694 |
. . . . . . 7
⊢ (𝜑 → (𝑇↑3) ∈ ℂ) |
| 15 | | 3z 11410 |
. . . . . . . . 9
⊢ 3 ∈
ℤ |
| 16 | 15 | a1i 11 |
. . . . . . . 8
⊢ (𝜑 → 3 ∈
ℤ) |
| 17 | 2, 3, 16 | expne0d 13014 |
. . . . . . 7
⊢ (𝜑 → (𝑇↑3) ≠ 0) |
| 18 | 14, 17 | dividd 10799 |
. . . . . 6
⊢ (𝜑 → ((𝑇↑3) / (𝑇↑3)) = 1) |
| 19 | 12, 18 | eqtr3d 2658 |
. . . . 5
⊢ (𝜑 → ((𝐺 − 𝑁) / (𝑇↑3)) = 1) |
| 20 | 10, 19 | sylan9eqr 2678 |
. . . 4
⊢ ((𝜑 ∧ (𝑈↑3) = (𝐺 − 𝑁)) → ((𝑈↑3) / (𝑇↑3)) = 1) |
| 21 | 9, 20 | eqtrd 2656 |
. . 3
⊢ ((𝜑 ∧ (𝑈↑3) = (𝐺 − 𝑁)) → ((𝑈 / 𝑇)↑3) = 1) |
| 22 | | dcubic2.2 |
. . . . 5
⊢ (𝜑 → 𝑋 = (𝑈 − (𝑀 / 𝑈))) |
| 23 | 1, 2, 3 | divcan1d 10802 |
. . . . . 6
⊢ (𝜑 → ((𝑈 / 𝑇) · 𝑇) = 𝑈) |
| 24 | 23 | oveq2d 6666 |
. . . . . 6
⊢ (𝜑 → (𝑀 / ((𝑈 / 𝑇) · 𝑇)) = (𝑀 / 𝑈)) |
| 25 | 23, 24 | oveq12d 6668 |
. . . . 5
⊢ (𝜑 → (((𝑈 / 𝑇) · 𝑇) − (𝑀 / ((𝑈 / 𝑇) · 𝑇))) = (𝑈 − (𝑀 / 𝑈))) |
| 26 | 22, 25 | eqtr4d 2659 |
. . . 4
⊢ (𝜑 → 𝑋 = (((𝑈 / 𝑇) · 𝑇) − (𝑀 / ((𝑈 / 𝑇) · 𝑇)))) |
| 27 | 26 | adantr 481 |
. . 3
⊢ ((𝜑 ∧ (𝑈↑3) = (𝐺 − 𝑁)) → 𝑋 = (((𝑈 / 𝑇) · 𝑇) − (𝑀 / ((𝑈 / 𝑇) · 𝑇)))) |
| 28 | | oveq1 6657 |
. . . . . 6
⊢ (𝑟 = (𝑈 / 𝑇) → (𝑟↑3) = ((𝑈 / 𝑇)↑3)) |
| 29 | 28 | eqeq1d 2624 |
. . . . 5
⊢ (𝑟 = (𝑈 / 𝑇) → ((𝑟↑3) = 1 ↔ ((𝑈 / 𝑇)↑3) = 1)) |
| 30 | | oveq1 6657 |
. . . . . . 7
⊢ (𝑟 = (𝑈 / 𝑇) → (𝑟 · 𝑇) = ((𝑈 / 𝑇) · 𝑇)) |
| 31 | 30 | oveq2d 6666 |
. . . . . . 7
⊢ (𝑟 = (𝑈 / 𝑇) → (𝑀 / (𝑟 · 𝑇)) = (𝑀 / ((𝑈 / 𝑇) · 𝑇))) |
| 32 | 30, 31 | oveq12d 6668 |
. . . . . 6
⊢ (𝑟 = (𝑈 / 𝑇) → ((𝑟 · 𝑇) − (𝑀 / (𝑟 · 𝑇))) = (((𝑈 / 𝑇) · 𝑇) − (𝑀 / ((𝑈 / 𝑇) · 𝑇)))) |
| 33 | 32 | eqeq2d 2632 |
. . . . 5
⊢ (𝑟 = (𝑈 / 𝑇) → (𝑋 = ((𝑟 · 𝑇) − (𝑀 / (𝑟 · 𝑇))) ↔ 𝑋 = (((𝑈 / 𝑇) · 𝑇) − (𝑀 / ((𝑈 / 𝑇) · 𝑇))))) |
| 34 | 29, 33 | anbi12d 747 |
. . . 4
⊢ (𝑟 = (𝑈 / 𝑇) → (((𝑟↑3) = 1 ∧ 𝑋 = ((𝑟 · 𝑇) − (𝑀 / (𝑟 · 𝑇)))) ↔ (((𝑈 / 𝑇)↑3) = 1 ∧ 𝑋 = (((𝑈 / 𝑇) · 𝑇) − (𝑀 / ((𝑈 / 𝑇) · 𝑇)))))) |
| 35 | 34 | rspcev 3309 |
. . 3
⊢ (((𝑈 / 𝑇) ∈ ℂ ∧ (((𝑈 / 𝑇)↑3) = 1 ∧ 𝑋 = (((𝑈 / 𝑇) · 𝑇) − (𝑀 / ((𝑈 / 𝑇) · 𝑇))))) → ∃𝑟 ∈ ℂ ((𝑟↑3) = 1 ∧ 𝑋 = ((𝑟 · 𝑇) − (𝑀 / (𝑟 · 𝑇))))) |
| 36 | 5, 21, 27, 35 | syl12anc 1324 |
. 2
⊢ ((𝜑 ∧ (𝑈↑3) = (𝐺 − 𝑁)) → ∃𝑟 ∈ ℂ ((𝑟↑3) = 1 ∧ 𝑋 = ((𝑟 · 𝑇) − (𝑀 / (𝑟 · 𝑇))))) |
| 37 | | dcubic.m |
. . . . . . . 8
⊢ (𝜑 → 𝑀 = (𝑃 / 3)) |
| 38 | | dcubic.c |
. . . . . . . . 9
⊢ (𝜑 → 𝑃 ∈ ℂ) |
| 39 | | 3cn 11095 |
. . . . . . . . . 10
⊢ 3 ∈
ℂ |
| 40 | 39 | a1i 11 |
. . . . . . . . 9
⊢ (𝜑 → 3 ∈
ℂ) |
| 41 | | 3ne0 11115 |
. . . . . . . . . 10
⊢ 3 ≠
0 |
| 42 | 41 | a1i 11 |
. . . . . . . . 9
⊢ (𝜑 → 3 ≠ 0) |
| 43 | 38, 40, 42 | divcld 10801 |
. . . . . . . 8
⊢ (𝜑 → (𝑃 / 3) ∈ ℂ) |
| 44 | 37, 43 | eqeltrd 2701 |
. . . . . . 7
⊢ (𝜑 → 𝑀 ∈ ℂ) |
| 45 | | dcubic2.z |
. . . . . . 7
⊢ (𝜑 → 𝑈 ≠ 0) |
| 46 | 44, 1, 45 | divcld 10801 |
. . . . . 6
⊢ (𝜑 → (𝑀 / 𝑈) ∈ ℂ) |
| 47 | 46 | negcld 10379 |
. . . . 5
⊢ (𝜑 → -(𝑀 / 𝑈) ∈ ℂ) |
| 48 | 47, 2, 3 | divcld 10801 |
. . . 4
⊢ (𝜑 → (-(𝑀 / 𝑈) / 𝑇) ∈ ℂ) |
| 49 | 48 | adantr 481 |
. . 3
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → (-(𝑀 / 𝑈) / 𝑇) ∈ ℂ) |
| 50 | 47, 2, 3, 7 | expdivd 13022 |
. . . . . 6
⊢ (𝜑 → ((-(𝑀 / 𝑈) / 𝑇)↑3) = ((-(𝑀 / 𝑈)↑3) / (𝑇↑3))) |
| 51 | 44, 1, 45 | divnegd 10814 |
. . . . . . . . 9
⊢ (𝜑 → -(𝑀 / 𝑈) = (-𝑀 / 𝑈)) |
| 52 | 51 | oveq1d 6665 |
. . . . . . . 8
⊢ (𝜑 → (-(𝑀 / 𝑈)↑3) = ((-𝑀 / 𝑈)↑3)) |
| 53 | 44 | negcld 10379 |
. . . . . . . . 9
⊢ (𝜑 → -𝑀 ∈ ℂ) |
| 54 | 53, 1, 45, 7 | expdivd 13022 |
. . . . . . . 8
⊢ (𝜑 → ((-𝑀 / 𝑈)↑3) = ((-𝑀↑3) / (𝑈↑3))) |
| 55 | 11 | oveq2d 6666 |
. . . . . . . . . . . . . 14
⊢ (𝜑 → ((𝐺 + 𝑁) · (𝑇↑3)) = ((𝐺 + 𝑁) · (𝐺 − 𝑁))) |
| 56 | | dcubic.g |
. . . . . . . . . . . . . . 15
⊢ (𝜑 → 𝐺 ∈ ℂ) |
| 57 | | dcubic.n |
. . . . . . . . . . . . . . . 16
⊢ (𝜑 → 𝑁 = (𝑄 / 2)) |
| 58 | | dcubic.d |
. . . . . . . . . . . . . . . . 17
⊢ (𝜑 → 𝑄 ∈ ℂ) |
| 59 | 58 | halfcld 11277 |
. . . . . . . . . . . . . . . 16
⊢ (𝜑 → (𝑄 / 2) ∈ ℂ) |
| 60 | 57, 59 | eqeltrd 2701 |
. . . . . . . . . . . . . . 15
⊢ (𝜑 → 𝑁 ∈ ℂ) |
| 61 | | subsq 12972 |
. . . . . . . . . . . . . . 15
⊢ ((𝐺 ∈ ℂ ∧ 𝑁 ∈ ℂ) → ((𝐺↑2) − (𝑁↑2)) = ((𝐺 + 𝑁) · (𝐺 − 𝑁))) |
| 62 | 56, 60, 61 | syl2anc 693 |
. . . . . . . . . . . . . 14
⊢ (𝜑 → ((𝐺↑2) − (𝑁↑2)) = ((𝐺 + 𝑁) · (𝐺 − 𝑁))) |
| 63 | 55, 62 | eqtr4d 2659 |
. . . . . . . . . . . . 13
⊢ (𝜑 → ((𝐺 + 𝑁) · (𝑇↑3)) = ((𝐺↑2) − (𝑁↑2))) |
| 64 | | dcubic.2 |
. . . . . . . . . . . . . 14
⊢ (𝜑 → (𝐺↑2) = ((𝑁↑2) + (𝑀↑3))) |
| 65 | 64 | oveq1d 6665 |
. . . . . . . . . . . . 13
⊢ (𝜑 → ((𝐺↑2) − (𝑁↑2)) = (((𝑁↑2) + (𝑀↑3)) − (𝑁↑2))) |
| 66 | 60 | sqcld 13006 |
. . . . . . . . . . . . . 14
⊢ (𝜑 → (𝑁↑2) ∈ ℂ) |
| 67 | | expcl 12878 |
. . . . . . . . . . . . . . 15
⊢ ((𝑀 ∈ ℂ ∧ 3 ∈
ℕ0) → (𝑀↑3) ∈ ℂ) |
| 68 | 44, 6, 67 | sylancl 694 |
. . . . . . . . . . . . . 14
⊢ (𝜑 → (𝑀↑3) ∈ ℂ) |
| 69 | 66, 68 | pncan2d 10394 |
. . . . . . . . . . . . 13
⊢ (𝜑 → (((𝑁↑2) + (𝑀↑3)) − (𝑁↑2)) = (𝑀↑3)) |
| 70 | 63, 65, 69 | 3eqtrd 2660 |
. . . . . . . . . . . 12
⊢ (𝜑 → ((𝐺 + 𝑁) · (𝑇↑3)) = (𝑀↑3)) |
| 71 | 70 | negeqd 10275 |
. . . . . . . . . . 11
⊢ (𝜑 → -((𝐺 + 𝑁) · (𝑇↑3)) = -(𝑀↑3)) |
| 72 | 56, 60 | addcld 10059 |
. . . . . . . . . . . 12
⊢ (𝜑 → (𝐺 + 𝑁) ∈ ℂ) |
| 73 | 72, 14 | mulneg1d 10483 |
. . . . . . . . . . 11
⊢ (𝜑 → (-(𝐺 + 𝑁) · (𝑇↑3)) = -((𝐺 + 𝑁) · (𝑇↑3))) |
| 74 | | 3nn 11186 |
. . . . . . . . . . . . 13
⊢ 3 ∈
ℕ |
| 75 | 74 | a1i 11 |
. . . . . . . . . . . 12
⊢ (𝜑 → 3 ∈
ℕ) |
| 76 | | 2nn 11185 |
. . . . . . . . . . . . . 14
⊢ 2 ∈
ℕ |
| 77 | | 1nn0 11308 |
. . . . . . . . . . . . . 14
⊢ 1 ∈
ℕ0 |
| 78 | | 1nn 11031 |
. . . . . . . . . . . . . 14
⊢ 1 ∈
ℕ |
| 79 | | 2t1e2 11176 |
. . . . . . . . . . . . . . . 16
⊢ (2
· 1) = 2 |
| 80 | 79 | oveq1i 6660 |
. . . . . . . . . . . . . . 15
⊢ ((2
· 1) + 1) = (2 + 1) |
| 81 | | 2p1e3 11151 |
. . . . . . . . . . . . . . 15
⊢ (2 + 1) =
3 |
| 82 | 80, 81 | eqtri 2644 |
. . . . . . . . . . . . . 14
⊢ ((2
· 1) + 1) = 3 |
| 83 | | 1lt2 11194 |
. . . . . . . . . . . . . 14
⊢ 1 <
2 |
| 84 | 76, 77, 78, 82, 83 | ndvdsi 15136 |
. . . . . . . . . . . . 13
⊢ ¬ 2
∥ 3 |
| 85 | 84 | a1i 11 |
. . . . . . . . . . . 12
⊢ (𝜑 → ¬ 2 ∥
3) |
| 86 | | oexpneg 15069 |
. . . . . . . . . . . 12
⊢ ((𝑀 ∈ ℂ ∧ 3 ∈
ℕ ∧ ¬ 2 ∥ 3) → (-𝑀↑3) = -(𝑀↑3)) |
| 87 | 44, 75, 85, 86 | syl3anc 1326 |
. . . . . . . . . . 11
⊢ (𝜑 → (-𝑀↑3) = -(𝑀↑3)) |
| 88 | 71, 73, 87 | 3eqtr4d 2666 |
. . . . . . . . . 10
⊢ (𝜑 → (-(𝐺 + 𝑁) · (𝑇↑3)) = (-𝑀↑3)) |
| 89 | 88 | oveq1d 6665 |
. . . . . . . . 9
⊢ (𝜑 → ((-(𝐺 + 𝑁) · (𝑇↑3)) / (𝑈↑3)) = ((-𝑀↑3) / (𝑈↑3))) |
| 90 | 72 | negcld 10379 |
. . . . . . . . . 10
⊢ (𝜑 → -(𝐺 + 𝑁) ∈ ℂ) |
| 91 | | expcl 12878 |
. . . . . . . . . . 11
⊢ ((𝑈 ∈ ℂ ∧ 3 ∈
ℕ0) → (𝑈↑3) ∈ ℂ) |
| 92 | 1, 6, 91 | sylancl 694 |
. . . . . . . . . 10
⊢ (𝜑 → (𝑈↑3) ∈ ℂ) |
| 93 | 1, 45, 16 | expne0d 13014 |
. . . . . . . . . 10
⊢ (𝜑 → (𝑈↑3) ≠ 0) |
| 94 | 90, 14, 92, 93 | div23d 10838 |
. . . . . . . . 9
⊢ (𝜑 → ((-(𝐺 + 𝑁) · (𝑇↑3)) / (𝑈↑3)) = ((-(𝐺 + 𝑁) / (𝑈↑3)) · (𝑇↑3))) |
| 95 | 89, 94 | eqtr3d 2658 |
. . . . . . . 8
⊢ (𝜑 → ((-𝑀↑3) / (𝑈↑3)) = ((-(𝐺 + 𝑁) / (𝑈↑3)) · (𝑇↑3))) |
| 96 | 52, 54, 95 | 3eqtrd 2660 |
. . . . . . 7
⊢ (𝜑 → (-(𝑀 / 𝑈)↑3) = ((-(𝐺 + 𝑁) / (𝑈↑3)) · (𝑇↑3))) |
| 97 | 96 | oveq1d 6665 |
. . . . . 6
⊢ (𝜑 → ((-(𝑀 / 𝑈)↑3) / (𝑇↑3)) = (((-(𝐺 + 𝑁) / (𝑈↑3)) · (𝑇↑3)) / (𝑇↑3))) |
| 98 | 90, 92, 93 | divcld 10801 |
. . . . . . 7
⊢ (𝜑 → (-(𝐺 + 𝑁) / (𝑈↑3)) ∈ ℂ) |
| 99 | 98, 14, 17 | divcan4d 10807 |
. . . . . 6
⊢ (𝜑 → (((-(𝐺 + 𝑁) / (𝑈↑3)) · (𝑇↑3)) / (𝑇↑3)) = (-(𝐺 + 𝑁) / (𝑈↑3))) |
| 100 | 50, 97, 99 | 3eqtrd 2660 |
. . . . 5
⊢ (𝜑 → ((-(𝑀 / 𝑈) / 𝑇)↑3) = (-(𝐺 + 𝑁) / (𝑈↑3))) |
| 101 | 100 | adantr 481 |
. . . 4
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → ((-(𝑀 / 𝑈) / 𝑇)↑3) = (-(𝐺 + 𝑁) / (𝑈↑3))) |
| 102 | | oveq1 6657 |
. . . . . 6
⊢ ((𝑈↑3) = -(𝐺 + 𝑁) → ((𝑈↑3) / (𝑈↑3)) = (-(𝐺 + 𝑁) / (𝑈↑3))) |
| 103 | 102 | eqcomd 2628 |
. . . . 5
⊢ ((𝑈↑3) = -(𝐺 + 𝑁) → (-(𝐺 + 𝑁) / (𝑈↑3)) = ((𝑈↑3) / (𝑈↑3))) |
| 104 | 92, 93 | dividd 10799 |
. . . . 5
⊢ (𝜑 → ((𝑈↑3) / (𝑈↑3)) = 1) |
| 105 | 103, 104 | sylan9eqr 2678 |
. . . 4
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → (-(𝐺 + 𝑁) / (𝑈↑3)) = 1) |
| 106 | 101, 105 | eqtrd 2656 |
. . 3
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → ((-(𝑀 / 𝑈) / 𝑇)↑3) = 1) |
| 107 | 46, 1 | neg2subd 10409 |
. . . . . 6
⊢ (𝜑 → (-(𝑀 / 𝑈) − -𝑈) = (𝑈 − (𝑀 / 𝑈))) |
| 108 | 22, 107 | eqtr4d 2659 |
. . . . 5
⊢ (𝜑 → 𝑋 = (-(𝑀 / 𝑈) − -𝑈)) |
| 109 | 108 | adantr 481 |
. . . 4
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → 𝑋 = (-(𝑀 / 𝑈) − -𝑈)) |
| 110 | 47, 2, 3 | divcan1d 10802 |
. . . . . 6
⊢ (𝜑 → ((-(𝑀 / 𝑈) / 𝑇) · 𝑇) = -(𝑀 / 𝑈)) |
| 111 | 110 | adantr 481 |
. . . . 5
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → ((-(𝑀 / 𝑈) / 𝑇) · 𝑇) = -(𝑀 / 𝑈)) |
| 112 | 44, 1, 45 | divneg2d 10815 |
. . . . . . . . 9
⊢ (𝜑 → -(𝑀 / 𝑈) = (𝑀 / -𝑈)) |
| 113 | 110, 112 | eqtrd 2656 |
. . . . . . . 8
⊢ (𝜑 → ((-(𝑀 / 𝑈) / 𝑇) · 𝑇) = (𝑀 / -𝑈)) |
| 114 | 113 | adantr 481 |
. . . . . . 7
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → ((-(𝑀 / 𝑈) / 𝑇) · 𝑇) = (𝑀 / -𝑈)) |
| 115 | 114 | oveq2d 6666 |
. . . . . 6
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → (𝑀 / ((-(𝑀 / 𝑈) / 𝑇) · 𝑇)) = (𝑀 / (𝑀 / -𝑈))) |
| 116 | 44 | adantr 481 |
. . . . . . 7
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → 𝑀 ∈ ℂ) |
| 117 | 1 | negcld 10379 |
. . . . . . . 8
⊢ (𝜑 → -𝑈 ∈ ℂ) |
| 118 | 117 | adantr 481 |
. . . . . . 7
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → -𝑈 ∈ ℂ) |
| 119 | 73, 71 | eqtrd 2656 |
. . . . . . . . . 10
⊢ (𝜑 → (-(𝐺 + 𝑁) · (𝑇↑3)) = -(𝑀↑3)) |
| 120 | 119 | adantr 481 |
. . . . . . . . 9
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → (-(𝐺 + 𝑁) · (𝑇↑3)) = -(𝑀↑3)) |
| 121 | 90 | adantr 481 |
. . . . . . . . . 10
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → -(𝐺 + 𝑁) ∈ ℂ) |
| 122 | 14 | adantr 481 |
. . . . . . . . . 10
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → (𝑇↑3) ∈ ℂ) |
| 123 | | simpr 477 |
. . . . . . . . . . 11
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → (𝑈↑3) = -(𝐺 + 𝑁)) |
| 124 | 93 | adantr 481 |
. . . . . . . . . . 11
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → (𝑈↑3) ≠ 0) |
| 125 | 123, 124 | eqnetrrd 2862 |
. . . . . . . . . 10
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → -(𝐺 + 𝑁) ≠ 0) |
| 126 | 17 | adantr 481 |
. . . . . . . . . 10
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → (𝑇↑3) ≠ 0) |
| 127 | 121, 122,
125, 126 | mulne0d 10679 |
. . . . . . . . 9
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → (-(𝐺 + 𝑁) · (𝑇↑3)) ≠ 0) |
| 128 | 120, 127 | eqnetrrd 2862 |
. . . . . . . 8
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → -(𝑀↑3) ≠ 0) |
| 129 | | oveq1 6657 |
. . . . . . . . . . . 12
⊢ (𝑀 = 0 → (𝑀↑3) = (0↑3)) |
| 130 | | 0exp 12895 |
. . . . . . . . . . . . 13
⊢ (3 ∈
ℕ → (0↑3) = 0) |
| 131 | 74, 130 | ax-mp 5 |
. . . . . . . . . . . 12
⊢
(0↑3) = 0 |
| 132 | 129, 131 | syl6eq 2672 |
. . . . . . . . . . 11
⊢ (𝑀 = 0 → (𝑀↑3) = 0) |
| 133 | 132 | negeqd 10275 |
. . . . . . . . . 10
⊢ (𝑀 = 0 → -(𝑀↑3) = -0) |
| 134 | | neg0 10327 |
. . . . . . . . . 10
⊢ -0 =
0 |
| 135 | 133, 134 | syl6eq 2672 |
. . . . . . . . 9
⊢ (𝑀 = 0 → -(𝑀↑3) = 0) |
| 136 | 135 | necon3i 2826 |
. . . . . . . 8
⊢ (-(𝑀↑3) ≠ 0 → 𝑀 ≠ 0) |
| 137 | 128, 136 | syl 17 |
. . . . . . 7
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → 𝑀 ≠ 0) |
| 138 | 1, 45 | negne0d 10390 |
. . . . . . . 8
⊢ (𝜑 → -𝑈 ≠ 0) |
| 139 | 138 | adantr 481 |
. . . . . . 7
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → -𝑈 ≠ 0) |
| 140 | 116, 118,
137, 139 | ddcand 10821 |
. . . . . 6
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → (𝑀 / (𝑀 / -𝑈)) = -𝑈) |
| 141 | 115, 140 | eqtrd 2656 |
. . . . 5
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → (𝑀 / ((-(𝑀 / 𝑈) / 𝑇) · 𝑇)) = -𝑈) |
| 142 | 111, 141 | oveq12d 6668 |
. . . 4
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → (((-(𝑀 / 𝑈) / 𝑇) · 𝑇) − (𝑀 / ((-(𝑀 / 𝑈) / 𝑇) · 𝑇))) = (-(𝑀 / 𝑈) − -𝑈)) |
| 143 | 109, 142 | eqtr4d 2659 |
. . 3
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → 𝑋 = (((-(𝑀 / 𝑈) / 𝑇) · 𝑇) − (𝑀 / ((-(𝑀 / 𝑈) / 𝑇) · 𝑇)))) |
| 144 | | oveq1 6657 |
. . . . . 6
⊢ (𝑟 = (-(𝑀 / 𝑈) / 𝑇) → (𝑟↑3) = ((-(𝑀 / 𝑈) / 𝑇)↑3)) |
| 145 | 144 | eqeq1d 2624 |
. . . . 5
⊢ (𝑟 = (-(𝑀 / 𝑈) / 𝑇) → ((𝑟↑3) = 1 ↔ ((-(𝑀 / 𝑈) / 𝑇)↑3) = 1)) |
| 146 | | oveq1 6657 |
. . . . . . 7
⊢ (𝑟 = (-(𝑀 / 𝑈) / 𝑇) → (𝑟 · 𝑇) = ((-(𝑀 / 𝑈) / 𝑇) · 𝑇)) |
| 147 | 146 | oveq2d 6666 |
. . . . . . 7
⊢ (𝑟 = (-(𝑀 / 𝑈) / 𝑇) → (𝑀 / (𝑟 · 𝑇)) = (𝑀 / ((-(𝑀 / 𝑈) / 𝑇) · 𝑇))) |
| 148 | 146, 147 | oveq12d 6668 |
. . . . . 6
⊢ (𝑟 = (-(𝑀 / 𝑈) / 𝑇) → ((𝑟 · 𝑇) − (𝑀 / (𝑟 · 𝑇))) = (((-(𝑀 / 𝑈) / 𝑇) · 𝑇) − (𝑀 / ((-(𝑀 / 𝑈) / 𝑇) · 𝑇)))) |
| 149 | 148 | eqeq2d 2632 |
. . . . 5
⊢ (𝑟 = (-(𝑀 / 𝑈) / 𝑇) → (𝑋 = ((𝑟 · 𝑇) − (𝑀 / (𝑟 · 𝑇))) ↔ 𝑋 = (((-(𝑀 / 𝑈) / 𝑇) · 𝑇) − (𝑀 / ((-(𝑀 / 𝑈) / 𝑇) · 𝑇))))) |
| 150 | 145, 149 | anbi12d 747 |
. . . 4
⊢ (𝑟 = (-(𝑀 / 𝑈) / 𝑇) → (((𝑟↑3) = 1 ∧ 𝑋 = ((𝑟 · 𝑇) − (𝑀 / (𝑟 · 𝑇)))) ↔ (((-(𝑀 / 𝑈) / 𝑇)↑3) = 1 ∧ 𝑋 = (((-(𝑀 / 𝑈) / 𝑇) · 𝑇) − (𝑀 / ((-(𝑀 / 𝑈) / 𝑇) · 𝑇)))))) |
| 151 | 150 | rspcev 3309 |
. . 3
⊢
(((-(𝑀 / 𝑈) / 𝑇) ∈ ℂ ∧ (((-(𝑀 / 𝑈) / 𝑇)↑3) = 1 ∧ 𝑋 = (((-(𝑀 / 𝑈) / 𝑇) · 𝑇) − (𝑀 / ((-(𝑀 / 𝑈) / 𝑇) · 𝑇))))) → ∃𝑟 ∈ ℂ ((𝑟↑3) = 1 ∧ 𝑋 = ((𝑟 · 𝑇) − (𝑀 / (𝑟 · 𝑇))))) |
| 152 | 49, 106, 143, 151 | syl12anc 1324 |
. 2
⊢ ((𝜑 ∧ (𝑈↑3) = -(𝐺 + 𝑁)) → ∃𝑟 ∈ ℂ ((𝑟↑3) = 1 ∧ 𝑋 = ((𝑟 · 𝑇) − (𝑀 / (𝑟 · 𝑇))))) |
| 153 | 92 | sqcld 13006 |
. . . . . . 7
⊢ (𝜑 → ((𝑈↑3)↑2) ∈
ℂ) |
| 154 | 153 | mulid2d 10058 |
. . . . . 6
⊢ (𝜑 → (1 · ((𝑈↑3)↑2)) = ((𝑈↑3)↑2)) |
| 155 | 58, 92 | mulcld 10060 |
. . . . . . 7
⊢ (𝜑 → (𝑄 · (𝑈↑3)) ∈ ℂ) |
| 156 | 155, 68 | negsubd 10398 |
. . . . . 6
⊢ (𝜑 → ((𝑄 · (𝑈↑3)) + -(𝑀↑3)) = ((𝑄 · (𝑈↑3)) − (𝑀↑3))) |
| 157 | 154, 156 | oveq12d 6668 |
. . . . 5
⊢ (𝜑 → ((1 · ((𝑈↑3)↑2)) + ((𝑄 · (𝑈↑3)) + -(𝑀↑3))) = (((𝑈↑3)↑2) + ((𝑄 · (𝑈↑3)) − (𝑀↑3)))) |
| 158 | | dcubic2.x |
. . . . . 6
⊢ (𝜑 → ((𝑋↑3) + ((𝑃 · 𝑋) + 𝑄)) = 0) |
| 159 | | dcubic.x |
. . . . . . 7
⊢ (𝜑 → 𝑋 ∈ ℂ) |
| 160 | 38, 58, 159, 2, 11, 56, 64, 37, 57, 3, 1, 45, 22 | dcubic1lem 24570 |
. . . . . 6
⊢ (𝜑 → (((𝑋↑3) + ((𝑃 · 𝑋) + 𝑄)) = 0 ↔ (((𝑈↑3)↑2) + ((𝑄 · (𝑈↑3)) − (𝑀↑3))) = 0)) |
| 161 | 158, 160 | mpbid 222 |
. . . . 5
⊢ (𝜑 → (((𝑈↑3)↑2) + ((𝑄 · (𝑈↑3)) − (𝑀↑3))) = 0) |
| 162 | 157, 161 | eqtrd 2656 |
. . . 4
⊢ (𝜑 → ((1 · ((𝑈↑3)↑2)) + ((𝑄 · (𝑈↑3)) + -(𝑀↑3))) = 0) |
| 163 | | 1cnd 10056 |
. . . . 5
⊢ (𝜑 → 1 ∈
ℂ) |
| 164 | | ax-1ne0 10005 |
. . . . . 6
⊢ 1 ≠
0 |
| 165 | 164 | a1i 11 |
. . . . 5
⊢ (𝜑 → 1 ≠ 0) |
| 166 | 68 | negcld 10379 |
. . . . 5
⊢ (𝜑 → -(𝑀↑3) ∈ ℂ) |
| 167 | | 2cn 11091 |
. . . . . 6
⊢ 2 ∈
ℂ |
| 168 | | mulcl 10020 |
. . . . . 6
⊢ ((2
∈ ℂ ∧ 𝐺
∈ ℂ) → (2 · 𝐺) ∈ ℂ) |
| 169 | 167, 56, 168 | sylancr 695 |
. . . . 5
⊢ (𝜑 → (2 · 𝐺) ∈
ℂ) |
| 170 | | sqmul 12926 |
. . . . . . 7
⊢ ((2
∈ ℂ ∧ 𝐺
∈ ℂ) → ((2 · 𝐺)↑2) = ((2↑2) · (𝐺↑2))) |
| 171 | 167, 56, 170 | sylancr 695 |
. . . . . 6
⊢ (𝜑 → ((2 · 𝐺)↑2) = ((2↑2) ·
(𝐺↑2))) |
| 172 | 64 | oveq2d 6666 |
. . . . . 6
⊢ (𝜑 → ((2↑2) ·
(𝐺↑2)) = ((2↑2)
· ((𝑁↑2) +
(𝑀↑3)))) |
| 173 | 167 | sqcli 12944 |
. . . . . . . . 9
⊢
(2↑2) ∈ ℂ |
| 174 | | mulcl 10020 |
. . . . . . . . 9
⊢
(((2↑2) ∈ ℂ ∧ (𝑁↑2) ∈ ℂ) → ((2↑2)
· (𝑁↑2)) ∈
ℂ) |
| 175 | 173, 66, 174 | sylancr 695 |
. . . . . . . 8
⊢ (𝜑 → ((2↑2) ·
(𝑁↑2)) ∈
ℂ) |
| 176 | | mulcl 10020 |
. . . . . . . . 9
⊢
(((2↑2) ∈ ℂ ∧ (𝑀↑3) ∈ ℂ) → ((2↑2)
· (𝑀↑3)) ∈
ℂ) |
| 177 | 173, 68, 176 | sylancr 695 |
. . . . . . . 8
⊢ (𝜑 → ((2↑2) ·
(𝑀↑3)) ∈
ℂ) |
| 178 | 175, 177 | subnegd 10399 |
. . . . . . 7
⊢ (𝜑 → (((2↑2) ·
(𝑁↑2)) −
-((2↑2) · (𝑀↑3))) = (((2↑2) · (𝑁↑2)) + ((2↑2) ·
(𝑀↑3)))) |
| 179 | 57 | oveq2d 6666 |
. . . . . . . . . . 11
⊢ (𝜑 → (2 · 𝑁) = (2 · (𝑄 / 2))) |
| 180 | 167 | a1i 11 |
. . . . . . . . . . . 12
⊢ (𝜑 → 2 ∈
ℂ) |
| 181 | | 2ne0 11113 |
. . . . . . . . . . . . 13
⊢ 2 ≠
0 |
| 182 | 181 | a1i 11 |
. . . . . . . . . . . 12
⊢ (𝜑 → 2 ≠ 0) |
| 183 | 58, 180, 182 | divcan2d 10803 |
. . . . . . . . . . 11
⊢ (𝜑 → (2 · (𝑄 / 2)) = 𝑄) |
| 184 | 179, 183 | eqtrd 2656 |
. . . . . . . . . 10
⊢ (𝜑 → (2 · 𝑁) = 𝑄) |
| 185 | 184 | oveq1d 6665 |
. . . . . . . . 9
⊢ (𝜑 → ((2 · 𝑁)↑2) = (𝑄↑2)) |
| 186 | | sqmul 12926 |
. . . . . . . . . 10
⊢ ((2
∈ ℂ ∧ 𝑁
∈ ℂ) → ((2 · 𝑁)↑2) = ((2↑2) · (𝑁↑2))) |
| 187 | 167, 60, 186 | sylancr 695 |
. . . . . . . . 9
⊢ (𝜑 → ((2 · 𝑁)↑2) = ((2↑2) ·
(𝑁↑2))) |
| 188 | 185, 187 | eqtr3d 2658 |
. . . . . . . 8
⊢ (𝜑 → (𝑄↑2) = ((2↑2) · (𝑁↑2))) |
| 189 | 166 | mulid2d 10058 |
. . . . . . . . . . 11
⊢ (𝜑 → (1 · -(𝑀↑3)) = -(𝑀↑3)) |
| 190 | 189 | oveq2d 6666 |
. . . . . . . . . 10
⊢ (𝜑 → (4 · (1 ·
-(𝑀↑3))) = (4 ·
-(𝑀↑3))) |
| 191 | | 4cn 11098 |
. . . . . . . . . . 11
⊢ 4 ∈
ℂ |
| 192 | | mulneg2 10467 |
. . . . . . . . . . 11
⊢ ((4
∈ ℂ ∧ (𝑀↑3) ∈ ℂ) → (4 ·
-(𝑀↑3)) = -(4 ·
(𝑀↑3))) |
| 193 | 191, 68, 192 | sylancr 695 |
. . . . . . . . . 10
⊢ (𝜑 → (4 · -(𝑀↑3)) = -(4 · (𝑀↑3))) |
| 194 | 190, 193 | eqtrd 2656 |
. . . . . . . . 9
⊢ (𝜑 → (4 · (1 ·
-(𝑀↑3))) = -(4
· (𝑀↑3))) |
| 195 | | sq2 12960 |
. . . . . . . . . . 11
⊢
(2↑2) = 4 |
| 196 | 195 | oveq1i 6660 |
. . . . . . . . . 10
⊢
((2↑2) · (𝑀↑3)) = (4 · (𝑀↑3)) |
| 197 | 196 | negeqi 10274 |
. . . . . . . . 9
⊢
-((2↑2) · (𝑀↑3)) = -(4 · (𝑀↑3)) |
| 198 | 194, 197 | syl6eqr 2674 |
. . . . . . . 8
⊢ (𝜑 → (4 · (1 ·
-(𝑀↑3))) =
-((2↑2) · (𝑀↑3))) |
| 199 | 188, 198 | oveq12d 6668 |
. . . . . . 7
⊢ (𝜑 → ((𝑄↑2) − (4 · (1 ·
-(𝑀↑3)))) =
(((2↑2) · (𝑁↑2)) − -((2↑2) ·
(𝑀↑3)))) |
| 200 | 173 | a1i 11 |
. . . . . . . 8
⊢ (𝜑 → (2↑2) ∈
ℂ) |
| 201 | 200, 66, 68 | adddid 10064 |
. . . . . . 7
⊢ (𝜑 → ((2↑2) ·
((𝑁↑2) + (𝑀↑3))) = (((2↑2)
· (𝑁↑2)) +
((2↑2) · (𝑀↑3)))) |
| 202 | 178, 199,
201 | 3eqtr4rd 2667 |
. . . . . 6
⊢ (𝜑 → ((2↑2) ·
((𝑁↑2) + (𝑀↑3))) = ((𝑄↑2) − (4 · (1 ·
-(𝑀↑3))))) |
| 203 | 171, 172,
202 | 3eqtrd 2660 |
. . . . 5
⊢ (𝜑 → ((2 · 𝐺)↑2) = ((𝑄↑2) − (4 · (1 ·
-(𝑀↑3))))) |
| 204 | 163, 165,
58, 166, 92, 169, 203 | quad2 24566 |
. . . 4
⊢ (𝜑 → (((1 · ((𝑈↑3)↑2)) + ((𝑄 · (𝑈↑3)) + -(𝑀↑3))) = 0 ↔ ((𝑈↑3) = ((-𝑄 + (2 · 𝐺)) / (2 · 1)) ∨ (𝑈↑3) = ((-𝑄 − (2 · 𝐺)) / (2 · 1))))) |
| 205 | 162, 204 | mpbid 222 |
. . 3
⊢ (𝜑 → ((𝑈↑3) = ((-𝑄 + (2 · 𝐺)) / (2 · 1)) ∨ (𝑈↑3) = ((-𝑄 − (2 · 𝐺)) / (2 · 1)))) |
| 206 | 79 | oveq2i 6661 |
. . . . . 6
⊢ ((-𝑄 + (2 · 𝐺)) / (2 · 1)) = ((-𝑄 + (2 · 𝐺)) / 2) |
| 207 | 58 | negcld 10379 |
. . . . . . . 8
⊢ (𝜑 → -𝑄 ∈ ℂ) |
| 208 | 207, 169,
180, 182 | divdird 10839 |
. . . . . . 7
⊢ (𝜑 → ((-𝑄 + (2 · 𝐺)) / 2) = ((-𝑄 / 2) + ((2 · 𝐺) / 2))) |
| 209 | 57 | negeqd 10275 |
. . . . . . . . 9
⊢ (𝜑 → -𝑁 = -(𝑄 / 2)) |
| 210 | 58, 180, 182 | divnegd 10814 |
. . . . . . . . 9
⊢ (𝜑 → -(𝑄 / 2) = (-𝑄 / 2)) |
| 211 | 209, 210 | eqtr2d 2657 |
. . . . . . . 8
⊢ (𝜑 → (-𝑄 / 2) = -𝑁) |
| 212 | 56, 180, 182 | divcan3d 10806 |
. . . . . . . 8
⊢ (𝜑 → ((2 · 𝐺) / 2) = 𝐺) |
| 213 | 211, 212 | oveq12d 6668 |
. . . . . . 7
⊢ (𝜑 → ((-𝑄 / 2) + ((2 · 𝐺) / 2)) = (-𝑁 + 𝐺)) |
| 214 | 60 | negcld 10379 |
. . . . . . . . 9
⊢ (𝜑 → -𝑁 ∈ ℂ) |
| 215 | 214, 56 | addcomd 10238 |
. . . . . . . 8
⊢ (𝜑 → (-𝑁 + 𝐺) = (𝐺 + -𝑁)) |
| 216 | 56, 60 | negsubd 10398 |
. . . . . . . 8
⊢ (𝜑 → (𝐺 + -𝑁) = (𝐺 − 𝑁)) |
| 217 | 215, 216 | eqtrd 2656 |
. . . . . . 7
⊢ (𝜑 → (-𝑁 + 𝐺) = (𝐺 − 𝑁)) |
| 218 | 208, 213,
217 | 3eqtrd 2660 |
. . . . . 6
⊢ (𝜑 → ((-𝑄 + (2 · 𝐺)) / 2) = (𝐺 − 𝑁)) |
| 219 | 206, 218 | syl5eq 2668 |
. . . . 5
⊢ (𝜑 → ((-𝑄 + (2 · 𝐺)) / (2 · 1)) = (𝐺 − 𝑁)) |
| 220 | 219 | eqeq2d 2632 |
. . . 4
⊢ (𝜑 → ((𝑈↑3) = ((-𝑄 + (2 · 𝐺)) / (2 · 1)) ↔ (𝑈↑3) = (𝐺 − 𝑁))) |
| 221 | 79 | oveq2i 6661 |
. . . . . 6
⊢ ((-𝑄 − (2 · 𝐺)) / (2 · 1)) = ((-𝑄 − (2 · 𝐺)) / 2) |
| 222 | 211, 212 | oveq12d 6668 |
. . . . . . 7
⊢ (𝜑 → ((-𝑄 / 2) − ((2 · 𝐺) / 2)) = (-𝑁 − 𝐺)) |
| 223 | 207, 169,
180, 182 | divsubdird 10840 |
. . . . . . 7
⊢ (𝜑 → ((-𝑄 − (2 · 𝐺)) / 2) = ((-𝑄 / 2) − ((2 · 𝐺) / 2))) |
| 224 | 56, 60 | addcomd 10238 |
. . . . . . . . 9
⊢ (𝜑 → (𝐺 + 𝑁) = (𝑁 + 𝐺)) |
| 225 | 224 | negeqd 10275 |
. . . . . . . 8
⊢ (𝜑 → -(𝐺 + 𝑁) = -(𝑁 + 𝐺)) |
| 226 | 60, 56 | negdi2d 10406 |
. . . . . . . 8
⊢ (𝜑 → -(𝑁 + 𝐺) = (-𝑁 − 𝐺)) |
| 227 | 225, 226 | eqtrd 2656 |
. . . . . . 7
⊢ (𝜑 → -(𝐺 + 𝑁) = (-𝑁 − 𝐺)) |
| 228 | 222, 223,
227 | 3eqtr4d 2666 |
. . . . . 6
⊢ (𝜑 → ((-𝑄 − (2 · 𝐺)) / 2) = -(𝐺 + 𝑁)) |
| 229 | 221, 228 | syl5eq 2668 |
. . . . 5
⊢ (𝜑 → ((-𝑄 − (2 · 𝐺)) / (2 · 1)) = -(𝐺 + 𝑁)) |
| 230 | 229 | eqeq2d 2632 |
. . . 4
⊢ (𝜑 → ((𝑈↑3) = ((-𝑄 − (2 · 𝐺)) / (2 · 1)) ↔ (𝑈↑3) = -(𝐺 + 𝑁))) |
| 231 | 220, 230 | orbi12d 746 |
. . 3
⊢ (𝜑 → (((𝑈↑3) = ((-𝑄 + (2 · 𝐺)) / (2 · 1)) ∨ (𝑈↑3) = ((-𝑄 − (2 · 𝐺)) / (2 · 1))) ↔ ((𝑈↑3) = (𝐺 − 𝑁) ∨ (𝑈↑3) = -(𝐺 + 𝑁)))) |
| 232 | 205, 231 | mpbid 222 |
. 2
⊢ (𝜑 → ((𝑈↑3) = (𝐺 − 𝑁) ∨ (𝑈↑3) = -(𝐺 + 𝑁))) |
| 233 | 36, 152, 232 | mpjaodan 827 |
1
⊢ (𝜑 → ∃𝑟 ∈ ℂ ((𝑟↑3) = 1 ∧ 𝑋 = ((𝑟 · 𝑇) − (𝑀 / (𝑟 · 𝑇))))) |