Proof of Theorem cxpsqrtlem
| Step | Hyp | Ref
| Expression |
| 1 | | ax-icn 11193 |
. . 3
⊢ i ∈
ℂ |
| 2 | | sqrtcl 15385 |
. . . 4
⊢ (𝐴 ∈ ℂ →
(√‘𝐴) ∈
ℂ) |
| 3 | 2 | ad2antrr 726 |
. . 3
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ (√‘𝐴)
∈ ℂ) |
| 4 | | mulcl 11218 |
. . 3
⊢ ((i
∈ ℂ ∧ (√‘𝐴) ∈ ℂ) → (i ·
(√‘𝐴)) ∈
ℂ) |
| 5 | 1, 3, 4 | sylancr 587 |
. 2
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ (i · (√‘𝐴)) ∈ ℂ) |
| 6 | | imval 15131 |
. . . 4
⊢ ((i
· (√‘𝐴))
∈ ℂ → (ℑ‘(i · (√‘𝐴))) = (ℜ‘((i ·
(√‘𝐴)) /
i))) |
| 7 | 5, 6 | syl 17 |
. . 3
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ (ℑ‘(i · (√‘𝐴))) = (ℜ‘((i ·
(√‘𝐴)) /
i))) |
| 8 | | ine0 11677 |
. . . . . 6
⊢ i ≠
0 |
| 9 | | divcan3 11927 |
. . . . . 6
⊢
(((√‘𝐴)
∈ ℂ ∧ i ∈ ℂ ∧ i ≠ 0) → ((i ·
(√‘𝐴)) / i) =
(√‘𝐴)) |
| 10 | 1, 8, 9 | mp3an23 1455 |
. . . . 5
⊢
((√‘𝐴)
∈ ℂ → ((i · (√‘𝐴)) / i) = (√‘𝐴)) |
| 11 | 3, 10 | syl 17 |
. . . 4
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ ((i · (√‘𝐴)) / i) = (√‘𝐴)) |
| 12 | 11 | fveq2d 6885 |
. . 3
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ (ℜ‘((i · (√‘𝐴)) / i)) =
(ℜ‘(√‘𝐴))) |
| 13 | | halfre 12459 |
. . . . . . . . . . . . 13
⊢ (1 / 2)
∈ ℝ |
| 14 | 13 | recni 11254 |
. . . . . . . . . . . 12
⊢ (1 / 2)
∈ ℂ |
| 15 | | logcl 26534 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → (log‘𝐴) ∈
ℂ) |
| 16 | | mulcl 11218 |
. . . . . . . . . . . 12
⊢ (((1 / 2)
∈ ℂ ∧ (log‘𝐴) ∈ ℂ) → ((1 / 2) ·
(log‘𝐴)) ∈
ℂ) |
| 17 | 14, 15, 16 | sylancr 587 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → ((1 / 2)
· (log‘𝐴))
∈ ℂ) |
| 18 | 17 | recld 15218 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(ℜ‘((1 / 2) · (log‘𝐴))) ∈ ℝ) |
| 19 | 18 | reefcld 16109 |
. . . . . . . . 9
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(exp‘(ℜ‘((1 / 2) · (log‘𝐴)))) ∈ ℝ) |
| 20 | 17 | imcld 15219 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(ℑ‘((1 / 2) · (log‘𝐴))) ∈ ℝ) |
| 21 | 20 | recoscld 16167 |
. . . . . . . . 9
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(cos‘(ℑ‘((1 / 2) · (log‘𝐴)))) ∈ ℝ) |
| 22 | 18 | rpefcld 16128 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(exp‘(ℜ‘((1 / 2) · (log‘𝐴)))) ∈
ℝ+) |
| 23 | 22 | rpge0d 13060 |
. . . . . . . . 9
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → 0 ≤
(exp‘(ℜ‘((1 / 2) · (log‘𝐴))))) |
| 24 | | immul2 15161 |
. . . . . . . . . . . . 13
⊢ (((1 / 2)
∈ ℝ ∧ (log‘𝐴) ∈ ℂ) → (ℑ‘((1
/ 2) · (log‘𝐴))) = ((1 / 2) ·
(ℑ‘(log‘𝐴)))) |
| 25 | 13, 15, 24 | sylancr 587 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(ℑ‘((1 / 2) · (log‘𝐴))) = ((1 / 2) ·
(ℑ‘(log‘𝐴)))) |
| 26 | 15 | imcld 15219 |
. . . . . . . . . . . . . 14
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(ℑ‘(log‘𝐴)) ∈ ℝ) |
| 27 | 26 | recnd 11268 |
. . . . . . . . . . . . 13
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(ℑ‘(log‘𝐴)) ∈ ℂ) |
| 28 | | mulcom 11220 |
. . . . . . . . . . . . 13
⊢ (((1 / 2)
∈ ℂ ∧ (ℑ‘(log‘𝐴)) ∈ ℂ) → ((1 / 2) ·
(ℑ‘(log‘𝐴))) = ((ℑ‘(log‘𝐴)) · (1 /
2))) |
| 29 | 14, 27, 28 | sylancr 587 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → ((1 / 2)
· (ℑ‘(log‘𝐴))) = ((ℑ‘(log‘𝐴)) · (1 /
2))) |
| 30 | 25, 29 | eqtrd 2771 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(ℑ‘((1 / 2) · (log‘𝐴))) = ((ℑ‘(log‘𝐴)) · (1 /
2))) |
| 31 | | logimcl 26535 |
. . . . . . . . . . . . . . 15
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → (-π <
(ℑ‘(log‘𝐴)) ∧ (ℑ‘(log‘𝐴)) ≤ π)) |
| 32 | 31 | simpld 494 |
. . . . . . . . . . . . . 14
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → -π <
(ℑ‘(log‘𝐴))) |
| 33 | | pire 26423 |
. . . . . . . . . . . . . . . 16
⊢ π
∈ ℝ |
| 34 | 33 | renegcli 11549 |
. . . . . . . . . . . . . . 15
⊢ -π
∈ ℝ |
| 35 | | ltle 11328 |
. . . . . . . . . . . . . . 15
⊢ ((-π
∈ ℝ ∧ (ℑ‘(log‘𝐴)) ∈ ℝ) → (-π <
(ℑ‘(log‘𝐴)) → -π ≤
(ℑ‘(log‘𝐴)))) |
| 36 | 34, 26, 35 | sylancr 587 |
. . . . . . . . . . . . . 14
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → (-π <
(ℑ‘(log‘𝐴)) → -π ≤
(ℑ‘(log‘𝐴)))) |
| 37 | 32, 36 | mpd 15 |
. . . . . . . . . . . . 13
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → -π ≤
(ℑ‘(log‘𝐴))) |
| 38 | 31 | simprd 495 |
. . . . . . . . . . . . 13
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(ℑ‘(log‘𝐴)) ≤ π) |
| 39 | 34, 33 | elicc2i 13434 |
. . . . . . . . . . . . 13
⊢
((ℑ‘(log‘𝐴)) ∈ (-π[,]π) ↔
((ℑ‘(log‘𝐴)) ∈ ℝ ∧ -π ≤
(ℑ‘(log‘𝐴)) ∧ (ℑ‘(log‘𝐴)) ≤ π)) |
| 40 | 26, 37, 38, 39 | syl3anbrc 1344 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(ℑ‘(log‘𝐴)) ∈ (-π[,]π)) |
| 41 | | halfgt0 12461 |
. . . . . . . . . . . . . 14
⊢ 0 < (1
/ 2) |
| 42 | 13, 41 | elrpii 13016 |
. . . . . . . . . . . . 13
⊢ (1 / 2)
∈ ℝ+ |
| 43 | 33 | recni 11254 |
. . . . . . . . . . . . . . 15
⊢ π
∈ ℂ |
| 44 | | 2cn 12320 |
. . . . . . . . . . . . . . 15
⊢ 2 ∈
ℂ |
| 45 | | 2ne0 12349 |
. . . . . . . . . . . . . . 15
⊢ 2 ≠
0 |
| 46 | | divneg 11938 |
. . . . . . . . . . . . . . 15
⊢ ((π
∈ ℂ ∧ 2 ∈ ℂ ∧ 2 ≠ 0) → -(π / 2) =
(-π / 2)) |
| 47 | 43, 44, 45, 46 | mp3an 1463 |
. . . . . . . . . . . . . 14
⊢ -(π /
2) = (-π / 2) |
| 48 | 34 | recni 11254 |
. . . . . . . . . . . . . . 15
⊢ -π
∈ ℂ |
| 49 | 48, 44, 45 | divreci 11991 |
. . . . . . . . . . . . . 14
⊢ (-π /
2) = (-π · (1 / 2)) |
| 50 | 47, 49 | eqtr2i 2760 |
. . . . . . . . . . . . 13
⊢ (-π
· (1 / 2)) = -(π / 2) |
| 51 | 43, 44, 45 | divreci 11991 |
. . . . . . . . . . . . . 14
⊢ (π /
2) = (π · (1 / 2)) |
| 52 | 51 | eqcomi 2745 |
. . . . . . . . . . . . 13
⊢ (π
· (1 / 2)) = (π / 2) |
| 53 | 34, 33, 42, 50, 52 | iccdili 13513 |
. . . . . . . . . . . 12
⊢
((ℑ‘(log‘𝐴)) ∈ (-π[,]π) →
((ℑ‘(log‘𝐴)) · (1 / 2)) ∈ (-(π /
2)[,](π / 2))) |
| 54 | 40, 53 | syl 17 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
((ℑ‘(log‘𝐴)) · (1 / 2)) ∈ (-(π /
2)[,](π / 2))) |
| 55 | 30, 54 | eqeltrd 2835 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(ℑ‘((1 / 2) · (log‘𝐴))) ∈ (-(π / 2)[,](π /
2))) |
| 56 | | cosq14ge0 26477 |
. . . . . . . . . 10
⊢
((ℑ‘((1 / 2) · (log‘𝐴))) ∈ (-(π / 2)[,](π / 2)) →
0 ≤ (cos‘(ℑ‘((1 / 2) · (log‘𝐴))))) |
| 57 | 55, 56 | syl 17 |
. . . . . . . . 9
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → 0 ≤
(cos‘(ℑ‘((1 / 2) · (log‘𝐴))))) |
| 58 | 19, 21, 23, 57 | mulge0d 11819 |
. . . . . . . 8
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → 0 ≤
((exp‘(ℜ‘((1 / 2) · (log‘𝐴)))) · (cos‘(ℑ‘((1
/ 2) · (log‘𝐴)))))) |
| 59 | | cxpef 26631 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0 ∧ (1 / 2) ∈
ℂ) → (𝐴↑𝑐(1 / 2)) =
(exp‘((1 / 2) · (log‘𝐴)))) |
| 60 | 14, 59 | mp3an3 1452 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → (𝐴↑𝑐(1 /
2)) = (exp‘((1 / 2) · (log‘𝐴)))) |
| 61 | | efeul 16185 |
. . . . . . . . . . . 12
⊢ (((1 / 2)
· (log‘𝐴))
∈ ℂ → (exp‘((1 / 2) · (log‘𝐴))) = ((exp‘(ℜ‘((1 / 2)
· (log‘𝐴))))
· ((cos‘(ℑ‘((1 / 2) · (log‘𝐴)))) + (i ·
(sin‘(ℑ‘((1 / 2) · (log‘𝐴)))))))) |
| 62 | 17, 61 | syl 17 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → (exp‘((1 /
2) · (log‘𝐴)))
= ((exp‘(ℜ‘((1 / 2) · (log‘𝐴)))) · ((cos‘(ℑ‘((1
/ 2) · (log‘𝐴)))) + (i ·
(sin‘(ℑ‘((1 / 2) · (log‘𝐴)))))))) |
| 63 | 60, 62 | eqtrd 2771 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → (𝐴↑𝑐(1 /
2)) = ((exp‘(ℜ‘((1 / 2) · (log‘𝐴)))) · ((cos‘(ℑ‘((1
/ 2) · (log‘𝐴)))) + (i ·
(sin‘(ℑ‘((1 / 2) · (log‘𝐴)))))))) |
| 64 | 63 | fveq2d 6885 |
. . . . . . . . 9
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(ℜ‘(𝐴↑𝑐(1 / 2))) =
(ℜ‘((exp‘(ℜ‘((1 / 2) · (log‘𝐴)))) ·
((cos‘(ℑ‘((1 / 2) · (log‘𝐴)))) + (i ·
(sin‘(ℑ‘((1 / 2) · (log‘𝐴))))))))) |
| 65 | 21 | recnd 11268 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(cos‘(ℑ‘((1 / 2) · (log‘𝐴)))) ∈ ℂ) |
| 66 | 20 | resincld 16166 |
. . . . . . . . . . . . 13
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(sin‘(ℑ‘((1 / 2) · (log‘𝐴)))) ∈ ℝ) |
| 67 | 66 | recnd 11268 |
. . . . . . . . . . . 12
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(sin‘(ℑ‘((1 / 2) · (log‘𝐴)))) ∈ ℂ) |
| 68 | | mulcl 11218 |
. . . . . . . . . . . 12
⊢ ((i
∈ ℂ ∧ (sin‘(ℑ‘((1 / 2) ·
(log‘𝐴)))) ∈
ℂ) → (i · (sin‘(ℑ‘((1 / 2) ·
(log‘𝐴))))) ∈
ℂ) |
| 69 | 1, 67, 68 | sylancr 587 |
. . . . . . . . . . 11
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → (i ·
(sin‘(ℑ‘((1 / 2) · (log‘𝐴))))) ∈ ℂ) |
| 70 | 65, 69 | addcld 11259 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
((cos‘(ℑ‘((1 / 2) · (log‘𝐴)))) + (i ·
(sin‘(ℑ‘((1 / 2) · (log‘𝐴)))))) ∈ ℂ) |
| 71 | 19, 70 | remul2d 15251 |
. . . . . . . . 9
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(ℜ‘((exp‘(ℜ‘((1 / 2) · (log‘𝐴)))) ·
((cos‘(ℑ‘((1 / 2) · (log‘𝐴)))) + (i ·
(sin‘(ℑ‘((1 / 2) · (log‘𝐴)))))))) = ((exp‘(ℜ‘((1 /
2) · (log‘𝐴)))) ·
(ℜ‘((cos‘(ℑ‘((1 / 2) · (log‘𝐴)))) + (i ·
(sin‘(ℑ‘((1 / 2) · (log‘𝐴))))))))) |
| 72 | 21, 66 | crred 15255 |
. . . . . . . . . 10
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(ℜ‘((cos‘(ℑ‘((1 / 2) · (log‘𝐴)))) + (i ·
(sin‘(ℑ‘((1 / 2) · (log‘𝐴))))))) = (cos‘(ℑ‘((1 / 2)
· (log‘𝐴))))) |
| 73 | 72 | oveq2d 7426 |
. . . . . . . . 9
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
((exp‘(ℜ‘((1 / 2) · (log‘𝐴)))) ·
(ℜ‘((cos‘(ℑ‘((1 / 2) · (log‘𝐴)))) + (i ·
(sin‘(ℑ‘((1 / 2) · (log‘𝐴)))))))) = ((exp‘(ℜ‘((1 /
2) · (log‘𝐴)))) · (cos‘(ℑ‘((1
/ 2) · (log‘𝐴)))))) |
| 74 | 64, 71, 73 | 3eqtrd 2775 |
. . . . . . . 8
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) →
(ℜ‘(𝐴↑𝑐(1 / 2))) =
((exp‘(ℜ‘((1 / 2) · (log‘𝐴)))) · (cos‘(ℑ‘((1
/ 2) · (log‘𝐴)))))) |
| 75 | 58, 74 | breqtrrd 5152 |
. . . . . . 7
⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → 0 ≤
(ℜ‘(𝐴↑𝑐(1 /
2)))) |
| 76 | 75 | adantr 480 |
. . . . . 6
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ 0 ≤ (ℜ‘(𝐴↑𝑐(1 /
2)))) |
| 77 | | simpr 484 |
. . . . . . . 8
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ (𝐴↑𝑐(1 / 2)) =
-(√‘𝐴)) |
| 78 | 77 | fveq2d 6885 |
. . . . . . 7
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ (ℜ‘(𝐴↑𝑐(1 / 2))) =
(ℜ‘-(√‘𝐴))) |
| 79 | 3 | renegd 15233 |
. . . . . . 7
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ (ℜ‘-(√‘𝐴)) = -(ℜ‘(√‘𝐴))) |
| 80 | 78, 79 | eqtrd 2771 |
. . . . . 6
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ (ℜ‘(𝐴↑𝑐(1 / 2))) =
-(ℜ‘(√‘𝐴))) |
| 81 | 76, 80 | breqtrd 5150 |
. . . . 5
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ 0 ≤ -(ℜ‘(√‘𝐴))) |
| 82 | 3 | recld 15218 |
. . . . . 6
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ (ℜ‘(√‘𝐴)) ∈ ℝ) |
| 83 | 82 | le0neg1d 11813 |
. . . . 5
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ ((ℜ‘(√‘𝐴)) ≤ 0 ↔ 0 ≤
-(ℜ‘(√‘𝐴)))) |
| 84 | 81, 83 | mpbird 257 |
. . . 4
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ (ℜ‘(√‘𝐴)) ≤ 0) |
| 85 | | sqrtrege0 15389 |
. . . . 5
⊢ (𝐴 ∈ ℂ → 0 ≤
(ℜ‘(√‘𝐴))) |
| 86 | 85 | ad2antrr 726 |
. . . 4
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ 0 ≤ (ℜ‘(√‘𝐴))) |
| 87 | | 0re 11242 |
. . . . 5
⊢ 0 ∈
ℝ |
| 88 | | letri3 11325 |
. . . . 5
⊢
(((ℜ‘(√‘𝐴)) ∈ ℝ ∧ 0 ∈ ℝ)
→ ((ℜ‘(√‘𝐴)) = 0 ↔
((ℜ‘(√‘𝐴)) ≤ 0 ∧ 0 ≤
(ℜ‘(√‘𝐴))))) |
| 89 | 82, 87, 88 | sylancl 586 |
. . . 4
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ ((ℜ‘(√‘𝐴)) = 0 ↔
((ℜ‘(√‘𝐴)) ≤ 0 ∧ 0 ≤
(ℜ‘(√‘𝐴))))) |
| 90 | 84, 86, 89 | mpbir2and 713 |
. . 3
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ (ℜ‘(√‘𝐴)) = 0) |
| 91 | 7, 12, 90 | 3eqtrd 2775 |
. 2
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ (ℑ‘(i · (√‘𝐴))) = 0) |
| 92 | 5, 91 | reim0bd 15224 |
1
⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑𝑐(1 /
2)) = -(√‘𝐴))
→ (i · (√‘𝐴)) ∈ ℝ) |