cxpsqrt - Metamath Proof Explorer

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Theorem cxpsqrt 26203

Description: The complex exponential function with exponent 1 / 2 exactly matches the complex square root function (the branch cut is in the same place for both functions), and thus serves as a suitable generalization to other 𝑛-th roots and irrational roots. (Contributed by Mario Carneiro, 2-Aug-2014.)

**Assertion**
Ref	Expression
cxpsqrt	⊢ (𝐴 ∈ ℂ → (𝐴↑_𝑐(1 / 2)) = (√‘𝐴))

**Proof of Theorem cxpsqrt**
Step	Hyp	Ref	Expression
1		halfcn 12424	. . . . . 6 ⊢ (1 / 2) ∈ ℂ
2		halfre 12423	. . . . . . 7 ⊢ (1 / 2) ∈ ℝ
3		halfgt0 12425	. . . . . . 7 ⊢ 0 < (1 / 2)
4	2, 3	gt0ne0ii 11747	. . . . . 6 ⊢ (1 / 2) ≠ 0
5		0cxp 26166	. . . . . 6 ⊢ (((1 / 2) ∈ ℂ ∧ (1 / 2) ≠ 0) → (0↑_𝑐(1 / 2)) = 0)
6	1, 4, 5	mp2an 691	. . . . 5 ⊢ (0↑_𝑐(1 / 2)) = 0
7		sqrt0 15185	. . . . 5 ⊢ (√‘0) = 0
8	6, 7	eqtr4i 2764	. . . 4 ⊢ (0↑_𝑐(1 / 2)) = (√‘0)
9		oveq1 7413	. . . 4 ⊢ (𝐴 = 0 → (𝐴↑_𝑐(1 / 2)) = (0↑_𝑐(1 / 2)))
10		fveq2 6889	. . . 4 ⊢ (𝐴 = 0 → (√‘𝐴) = (√‘0))
11	8, 9, 10	3eqtr4a 2799	. . 3 ⊢ (𝐴 = 0 → (𝐴↑_𝑐(1 / 2)) = (√‘𝐴))
12	11	a1i 11	. 2 ⊢ (𝐴 ∈ ℂ → (𝐴 = 0 → (𝐴↑_𝑐(1 / 2)) = (√‘𝐴)))
13		ax-icn 11166	. . . . . . . . . . . . . . . . 17 ⊢ i ∈ ℂ
14		sqrtcl 15305	. . . . . . . . . . . . . . . . . 18 ⊢ (𝐴 ∈ ℂ → (√‘𝐴) ∈ ℂ)
15	14	ad2antrr 725	. . . . . . . . . . . . . . . . 17 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (√‘𝐴) ∈ ℂ)
16		sqmul 14081	. . . . . . . . . . . . . . . . 17 ⊢ ((i ∈ ℂ ∧ (√‘𝐴) ∈ ℂ) → ((i · (√‘𝐴))↑2) = ((i↑2) · ((√‘𝐴)↑2)))
17	13, 15, 16	sylancr 588	. . . . . . . . . . . . . . . 16 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((i · (√‘𝐴))↑2) = ((i↑2) · ((√‘𝐴)↑2)))
18		i2 14163	. . . . . . . . . . . . . . . . . 18 ⊢ (i↑2) = -1
19	18	a1i 11	. . . . . . . . . . . . . . . . 17 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (i↑2) = -1)
20		sqrtth 15308	. . . . . . . . . . . . . . . . . 18 ⊢ (𝐴 ∈ ℂ → ((√‘𝐴)↑2) = 𝐴)
21	20	ad2antrr 725	. . . . . . . . . . . . . . . . 17 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((√‘𝐴)↑2) = 𝐴)
22	19, 21	oveq12d 7424	. . . . . . . . . . . . . . . 16 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((i↑2) · ((√‘𝐴)↑2)) = (-1 · 𝐴))
23		mulm1 11652	. . . . . . . . . . . . . . . . 17 ⊢ (𝐴 ∈ ℂ → (-1 · 𝐴) = -𝐴)
24	23	ad2antrr 725	. . . . . . . . . . . . . . . 16 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (-1 · 𝐴) = -𝐴)
25	17, 22, 24	3eqtrd 2777	. . . . . . . . . . . . . . 15 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((i · (√‘𝐴))↑2) = -𝐴)
26		cxpsqrtlem 26202	. . . . . . . . . . . . . . . 16 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (i · (√‘𝐴)) ∈ ℝ)
27	26	resqcld 14087	. . . . . . . . . . . . . . 15 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((i · (√‘𝐴))↑2) ∈ ℝ)
28	25, 27	eqeltrrd 2835	. . . . . . . . . . . . . 14 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → -𝐴 ∈ ℝ)
29		negeq0 11511	. . . . . . . . . . . . . . . . . . . . 21 ⊢ (𝐴 ∈ ℂ → (𝐴 = 0 ↔ -𝐴 = 0))
30	29	necon3bid 2986	. . . . . . . . . . . . . . . . . . . 20 ⊢ (𝐴 ∈ ℂ → (𝐴 ≠ 0 ↔ -𝐴 ≠ 0))
31	30	biimpa 478	. . . . . . . . . . . . . . . . . . 19 ⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → -𝐴 ≠ 0)
32	31	adantr 482	. . . . . . . . . . . . . . . . . 18 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → -𝐴 ≠ 0)
33	25, 32	eqnetrd 3009	. . . . . . . . . . . . . . . . 17 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((i · (√‘𝐴))↑2) ≠ 0)
34		sq0i 14154	. . . . . . . . . . . . . . . . . 18 ⊢ ((i · (√‘𝐴)) = 0 → ((i · (√‘𝐴))↑2) = 0)
35	34	necon3i 2974	. . . . . . . . . . . . . . . . 17 ⊢ (((i · (√‘𝐴))↑2) ≠ 0 → (i · (√‘𝐴)) ≠ 0)
36	33, 35	syl 17	. . . . . . . . . . . . . . . 16 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (i · (√‘𝐴)) ≠ 0)
37	26, 36	sqgt0d 14210	. . . . . . . . . . . . . . 15 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → 0 < ((i · (√‘𝐴))↑2))
38	37, 25	breqtrd 5174	. . . . . . . . . . . . . 14 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → 0 < -𝐴)
39	28, 38	elrpd 13010	. . . . . . . . . . . . 13 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → -𝐴 ∈ ℝ⁺)
40		logneg 26088	. . . . . . . . . . . . 13 ⊢ (-𝐴 ∈ ℝ⁺ → (log‘--𝐴) = ((log‘-𝐴) + (i · π)))
41	39, 40	syl 17	. . . . . . . . . . . 12 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (log‘--𝐴) = ((log‘-𝐴) + (i · π)))
42		negneg 11507	. . . . . . . . . . . . . 14 ⊢ (𝐴 ∈ ℂ → --𝐴 = 𝐴)
43	42	ad2antrr 725	. . . . . . . . . . . . 13 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → --𝐴 = 𝐴)
44	43	fveq2d 6893	. . . . . . . . . . . 12 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (log‘--𝐴) = (log‘𝐴))
45	39	relogcld 26123	. . . . . . . . . . . . . 14 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (log‘-𝐴) ∈ ℝ)
46	45	recnd 11239	. . . . . . . . . . . . 13 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (log‘-𝐴) ∈ ℂ)
47		picn 25961	. . . . . . . . . . . . . 14 ⊢ π ∈ ℂ
48	13, 47	mulcli 11218	. . . . . . . . . . . . 13 ⊢ (i · π) ∈ ℂ
49		addcom 11397	. . . . . . . . . . . . 13 ⊢ (((log‘-𝐴) ∈ ℂ ∧ (i · π) ∈ ℂ) → ((log‘-𝐴) + (i · π)) = ((i · π) + (log‘-𝐴)))
50	46, 48, 49	sylancl 587	. . . . . . . . . . . 12 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((log‘-𝐴) + (i · π)) = ((i · π) + (log‘-𝐴)))
51	41, 44, 50	3eqtr3d 2781	. . . . . . . . . . 11 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (log‘𝐴) = ((i · π) + (log‘-𝐴)))
52	51	oveq2d 7422	. . . . . . . . . 10 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((1 / 2) · (log‘𝐴)) = ((1 / 2) · ((i · π) + (log‘-𝐴))))
53		adddi 11196	. . . . . . . . . . 11 ⊢ (((1 / 2) ∈ ℂ ∧ (i · π) ∈ ℂ ∧ (log‘-𝐴) ∈ ℂ) → ((1 / 2) · ((i · π) + (log‘-𝐴))) = (((1 / 2) · (i · π)) + ((1 / 2) · (log‘-𝐴))))
54	1, 48, 46, 53	mp3an12i 1466	. . . . . . . . . 10 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((1 / 2) · ((i · π) + (log‘-𝐴))) = (((1 / 2) · (i · π)) + ((1 / 2) · (log‘-𝐴))))
55	52, 54	eqtrd 2773	. . . . . . . . 9 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((1 / 2) · (log‘𝐴)) = (((1 / 2) · (i · π)) + ((1 / 2) · (log‘-𝐴))))
56		2cn 12284	. . . . . . . . . . . 12 ⊢ 2 ∈ ℂ
57		2ne0 12313	. . . . . . . . . . . 12 ⊢ 2 ≠ 0
58		divrec2 11886	. . . . . . . . . . . 12 ⊢ (((i · π) ∈ ℂ ∧ 2 ∈ ℂ ∧ 2 ≠ 0) → ((i · π) / 2) = ((1 / 2) · (i · π)))
59	48, 56, 57, 58	mp3an 1462	. . . . . . . . . . 11 ⊢ ((i · π) / 2) = ((1 / 2) · (i · π))
60	13, 47, 56, 57	divassi 11967	. . . . . . . . . . 11 ⊢ ((i · π) / 2) = (i · (π / 2))
61	59, 60	eqtr3i 2763	. . . . . . . . . 10 ⊢ ((1 / 2) · (i · π)) = (i · (π / 2))
62	61	oveq1i 7416	. . . . . . . . 9 ⊢ (((1 / 2) · (i · π)) + ((1 / 2) · (log‘-𝐴))) = ((i · (π / 2)) + ((1 / 2) · (log‘-𝐴)))
63	55, 62	eqtrdi 2789	. . . . . . . 8 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((1 / 2) · (log‘𝐴)) = ((i · (π / 2)) + ((1 / 2) · (log‘-𝐴))))
64	63	fveq2d 6893	. . . . . . 7 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (exp‘((1 / 2) · (log‘𝐴))) = (exp‘((i · (π / 2)) + ((1 / 2) · (log‘-𝐴)))))
65	47, 56, 57	divcli 11953	. . . . . . . . 9 ⊢ (π / 2) ∈ ℂ
66	13, 65	mulcli 11218	. . . . . . . 8 ⊢ (i · (π / 2)) ∈ ℂ
67		mulcl 11191	. . . . . . . . 9 ⊢ (((1 / 2) ∈ ℂ ∧ (log‘-𝐴) ∈ ℂ) → ((1 / 2) · (log‘-𝐴)) ∈ ℂ)
68	1, 46, 67	sylancr 588	. . . . . . . 8 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((1 / 2) · (log‘-𝐴)) ∈ ℂ)
69		efadd 16034	. . . . . . . 8 ⊢ (((i · (π / 2)) ∈ ℂ ∧ ((1 / 2) · (log‘-𝐴)) ∈ ℂ) → (exp‘((i · (π / 2)) + ((1 / 2) · (log‘-𝐴)))) = ((exp‘(i · (π / 2))) · (exp‘((1 / 2) · (log‘-𝐴)))))
70	66, 68, 69	sylancr 588	. . . . . . 7 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (exp‘((i · (π / 2)) + ((1 / 2) · (log‘-𝐴)))) = ((exp‘(i · (π / 2))) · (exp‘((1 / 2) · (log‘-𝐴)))))
71		efhalfpi 25973	. . . . . . . . 9 ⊢ (exp‘(i · (π / 2))) = i
72	71	a1i 11	. . . . . . . 8 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (exp‘(i · (π / 2))) = i)
73		negcl 11457	. . . . . . . . . . 11 ⊢ (𝐴 ∈ ℂ → -𝐴 ∈ ℂ)
74	73	ad2antrr 725	. . . . . . . . . 10 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → -𝐴 ∈ ℂ)
75	1	a1i 11	. . . . . . . . . 10 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (1 / 2) ∈ ℂ)
76		cxpef 26165	. . . . . . . . . 10 ⊢ ((-𝐴 ∈ ℂ ∧ -𝐴 ≠ 0 ∧ (1 / 2) ∈ ℂ) → (-𝐴↑_𝑐(1 / 2)) = (exp‘((1 / 2) · (log‘-𝐴))))
77	74, 32, 75, 76	syl3anc 1372	. . . . . . . . 9 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (-𝐴↑_𝑐(1 / 2)) = (exp‘((1 / 2) · (log‘-𝐴))))
78		ax-1cn 11165	. . . . . . . . . . . . . 14 ⊢ 1 ∈ ℂ
79		2halves 12437	. . . . . . . . . . . . . 14 ⊢ (1 ∈ ℂ → ((1 / 2) + (1 / 2)) = 1)
80	78, 79	ax-mp 5	. . . . . . . . . . . . 13 ⊢ ((1 / 2) + (1 / 2)) = 1
81	80	oveq2i 7417	. . . . . . . . . . . 12 ⊢ (-𝐴↑_𝑐((1 / 2) + (1 / 2))) = (-𝐴↑_𝑐1)
82		cxp1 26171	. . . . . . . . . . . . 13 ⊢ (-𝐴 ∈ ℂ → (-𝐴↑_𝑐1) = -𝐴)
83	74, 82	syl 17	. . . . . . . . . . . 12 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (-𝐴↑_𝑐1) = -𝐴)
84	81, 83	eqtrid 2785	. . . . . . . . . . 11 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (-𝐴↑_𝑐((1 / 2) + (1 / 2))) = -𝐴)
85		rpcxpcl 26176	. . . . . . . . . . . . . . 15 ⊢ ((-𝐴 ∈ ℝ⁺ ∧ (1 / 2) ∈ ℝ) → (-𝐴↑_𝑐(1 / 2)) ∈ ℝ⁺)
86	39, 2, 85	sylancl 587	. . . . . . . . . . . . . 14 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (-𝐴↑_𝑐(1 / 2)) ∈ ℝ⁺)
87	86	rpcnd 13015	. . . . . . . . . . . . 13 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (-𝐴↑_𝑐(1 / 2)) ∈ ℂ)
88	87	sqvald 14105	. . . . . . . . . . . 12 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((-𝐴↑_𝑐(1 / 2))↑2) = ((-𝐴↑_𝑐(1 / 2)) · (-𝐴↑_𝑐(1 / 2))))
89		cxpadd 26179	. . . . . . . . . . . . 13 ⊢ (((-𝐴 ∈ ℂ ∧ -𝐴 ≠ 0) ∧ (1 / 2) ∈ ℂ ∧ (1 / 2) ∈ ℂ) → (-𝐴↑_𝑐((1 / 2) + (1 / 2))) = ((-𝐴↑_𝑐(1 / 2)) · (-𝐴↑_𝑐(1 / 2))))
90	74, 32, 75, 75, 89	syl211anc 1377	. . . . . . . . . . . 12 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (-𝐴↑_𝑐((1 / 2) + (1 / 2))) = ((-𝐴↑_𝑐(1 / 2)) · (-𝐴↑_𝑐(1 / 2))))
91	88, 90	eqtr4d 2776	. . . . . . . . . . 11 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((-𝐴↑_𝑐(1 / 2))↑2) = (-𝐴↑_𝑐((1 / 2) + (1 / 2))))
92	74	sqsqrtd 15383	. . . . . . . . . . 11 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((√‘-𝐴)↑2) = -𝐴)
93	84, 91, 92	3eqtr4d 2783	. . . . . . . . . 10 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((-𝐴↑_𝑐(1 / 2))↑2) = ((√‘-𝐴)↑2))
94	86	rprege0d 13020	. . . . . . . . . . 11 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((-𝐴↑_𝑐(1 / 2)) ∈ ℝ ∧ 0 ≤ (-𝐴↑_𝑐(1 / 2))))
95	39	rpsqrtcld 15355	. . . . . . . . . . . 12 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (√‘-𝐴) ∈ ℝ⁺)
96	95	rprege0d 13020	. . . . . . . . . . 11 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((√‘-𝐴) ∈ ℝ ∧ 0 ≤ (√‘-𝐴)))
97		sq11 14093	. . . . . . . . . . 11 ⊢ ((((-𝐴↑_𝑐(1 / 2)) ∈ ℝ ∧ 0 ≤ (-𝐴↑_𝑐(1 / 2))) ∧ ((√‘-𝐴) ∈ ℝ ∧ 0 ≤ (√‘-𝐴))) → (((-𝐴↑_𝑐(1 / 2))↑2) = ((√‘-𝐴)↑2) ↔ (-𝐴↑_𝑐(1 / 2)) = (√‘-𝐴)))
98	94, 96, 97	syl2anc 585	. . . . . . . . . 10 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (((-𝐴↑_𝑐(1 / 2))↑2) = ((√‘-𝐴)↑2) ↔ (-𝐴↑_𝑐(1 / 2)) = (√‘-𝐴)))
99	93, 98	mpbid 231	. . . . . . . . 9 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (-𝐴↑_𝑐(1 / 2)) = (√‘-𝐴))
100	77, 99	eqtr3d 2775	. . . . . . . 8 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (exp‘((1 / 2) · (log‘-𝐴))) = (√‘-𝐴))
101	72, 100	oveq12d 7424	. . . . . . 7 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → ((exp‘(i · (π / 2))) · (exp‘((1 / 2) · (log‘-𝐴)))) = (i · (√‘-𝐴)))
102	64, 70, 101	3eqtrd 2777	. . . . . 6 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (exp‘((1 / 2) · (log‘𝐴))) = (i · (√‘-𝐴)))
103		cxpef 26165	. . . . . . . 8 ⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0 ∧ (1 / 2) ∈ ℂ) → (𝐴↑_𝑐(1 / 2)) = (exp‘((1 / 2) · (log‘𝐴))))
104	1, 103	mp3an3 1451	. . . . . . 7 ⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → (𝐴↑_𝑐(1 / 2)) = (exp‘((1 / 2) · (log‘𝐴))))
105	104	adantr 482	. . . . . 6 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (𝐴↑_𝑐(1 / 2)) = (exp‘((1 / 2) · (log‘𝐴))))
106	43	fveq2d 6893	. . . . . . 7 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (√‘--𝐴) = (√‘𝐴))
107	39	rpge0d 13017	. . . . . . . 8 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → 0 ≤ -𝐴)
108	28, 107	sqrtnegd 15365	. . . . . . 7 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (√‘--𝐴) = (i · (√‘-𝐴)))
109	106, 108	eqtr3d 2775	. . . . . 6 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (√‘𝐴) = (i · (√‘-𝐴)))
110	102, 105, 109	3eqtr4d 2783	. . . . 5 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)) → (𝐴↑_𝑐(1 / 2)) = (√‘𝐴))
111	110	ex 414	. . . 4 ⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → ((𝐴↑_𝑐(1 / 2)) = -(√‘𝐴) → (𝐴↑_𝑐(1 / 2)) = (√‘𝐴)))
112	80	oveq2i 7417	. . . . . . . . 9 ⊢ (𝐴↑_𝑐((1 / 2) + (1 / 2))) = (𝐴↑_𝑐1)
113		cxpadd 26179	. . . . . . . . . 10 ⊢ (((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) ∧ (1 / 2) ∈ ℂ ∧ (1 / 2) ∈ ℂ) → (𝐴↑_𝑐((1 / 2) + (1 / 2))) = ((𝐴↑_𝑐(1 / 2)) · (𝐴↑_𝑐(1 / 2))))
114	1, 1, 113	mp3an23 1454	. . . . . . . . 9 ⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → (𝐴↑_𝑐((1 / 2) + (1 / 2))) = ((𝐴↑_𝑐(1 / 2)) · (𝐴↑_𝑐(1 / 2))))
115		cxp1 26171	. . . . . . . . . 10 ⊢ (𝐴 ∈ ℂ → (𝐴↑_𝑐1) = 𝐴)
116	115	adantr 482	. . . . . . . . 9 ⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → (𝐴↑_𝑐1) = 𝐴)
117	112, 114, 116	3eqtr3a 2797	. . . . . . . 8 ⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → ((𝐴↑_𝑐(1 / 2)) · (𝐴↑_𝑐(1 / 2))) = 𝐴)
118		cxpcl 26174	. . . . . . . . . . 11 ⊢ ((𝐴 ∈ ℂ ∧ (1 / 2) ∈ ℂ) → (𝐴↑_𝑐(1 / 2)) ∈ ℂ)
119	1, 118	mpan2 690	. . . . . . . . . 10 ⊢ (𝐴 ∈ ℂ → (𝐴↑_𝑐(1 / 2)) ∈ ℂ)
120	119	sqvald 14105	. . . . . . . . 9 ⊢ (𝐴 ∈ ℂ → ((𝐴↑_𝑐(1 / 2))↑2) = ((𝐴↑_𝑐(1 / 2)) · (𝐴↑_𝑐(1 / 2))))
121	120	adantr 482	. . . . . . . 8 ⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → ((𝐴↑_𝑐(1 / 2))↑2) = ((𝐴↑_𝑐(1 / 2)) · (𝐴↑_𝑐(1 / 2))))
122	20	adantr 482	. . . . . . . 8 ⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → ((√‘𝐴)↑2) = 𝐴)
123	117, 121, 122	3eqtr4d 2783	. . . . . . 7 ⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → ((𝐴↑_𝑐(1 / 2))↑2) = ((√‘𝐴)↑2))
124		sqeqor 14177	. . . . . . . . 9 ⊢ (((𝐴↑_𝑐(1 / 2)) ∈ ℂ ∧ (√‘𝐴) ∈ ℂ) → (((𝐴↑_𝑐(1 / 2))↑2) = ((√‘𝐴)↑2) ↔ ((𝐴↑_𝑐(1 / 2)) = (√‘𝐴) ∨ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴))))
125	119, 14, 124	syl2anc 585	. . . . . . . 8 ⊢ (𝐴 ∈ ℂ → (((𝐴↑_𝑐(1 / 2))↑2) = ((√‘𝐴)↑2) ↔ ((𝐴↑_𝑐(1 / 2)) = (√‘𝐴) ∨ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴))))
126	125	biimpa 478	. . . . . . 7 ⊢ ((𝐴 ∈ ℂ ∧ ((𝐴↑_𝑐(1 / 2))↑2) = ((√‘𝐴)↑2)) → ((𝐴↑_𝑐(1 / 2)) = (√‘𝐴) ∨ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)))
127	123, 126	syldan 592	. . . . . 6 ⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → ((𝐴↑_𝑐(1 / 2)) = (√‘𝐴) ∨ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)))
128	127	ord 863	. . . . 5 ⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → (¬ (𝐴↑_𝑐(1 / 2)) = (√‘𝐴) → (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴)))
129	128	con1d 145	. . . 4 ⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → (¬ (𝐴↑_𝑐(1 / 2)) = -(√‘𝐴) → (𝐴↑_𝑐(1 / 2)) = (√‘𝐴)))
130	111, 129	pm2.61d 179	. . 3 ⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ≠ 0) → (𝐴↑_𝑐(1 / 2)) = (√‘𝐴))
131	130	ex 414	. 2 ⊢ (𝐴 ∈ ℂ → (𝐴 ≠ 0 → (𝐴↑_𝑐(1 / 2)) = (√‘𝐴)))
132	12, 131	pm2.61dne 3029	1 ⊢ (𝐴 ∈ ℂ → (𝐴↑_𝑐(1 / 2)) = (√‘𝐴))

Colors of variables: wff setvar class

Syntax hints: → wi 4 ↔ wb 205 ∧ wa 397 ∨ wo 846 = wceq 1542 ∈ wcel 2107 ≠ wne 2941 class class class wbr 5148 ‘cfv 6541 (class class class)co 7406 ℂcc 11105 ℝcr 11106 0cc0 11107 1c1 11108 ici 11109 + caddc 11110 · cmul 11112 < clt 11245 ≤ cle 11246 -cneg 11442 / cdiv 11868 2c2 12264 ℝ⁺crp 12971 ↑cexp 14024 √csqrt 15177 expce 16002 πcpi 16007 logclog 26055 ↑_𝑐ccxp 26056

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1798 ax-4 1812 ax-5 1914 ax-6 1972 ax-7 2012 ax-8 2109 ax-9 2117 ax-10 2138 ax-11 2155 ax-12 2172 ax-ext 2704 ax-rep 5285 ax-sep 5299 ax-nul 5306 ax-pow 5363 ax-pr 5427 ax-un 7722 ax-inf2 9633 ax-cnex 11163 ax-resscn 11164 ax-1cn 11165 ax-icn 11166 ax-addcl 11167 ax-addrcl 11168 ax-mulcl 11169 ax-mulrcl 11170 ax-mulcom 11171 ax-addass 11172 ax-mulass 11173 ax-distr 11174 ax-i2m1 11175 ax-1ne0 11176 ax-1rid 11177 ax-rnegex 11178 ax-rrecex 11179 ax-cnre 11180 ax-pre-lttri 11181 ax-pre-lttrn 11182 ax-pre-ltadd 11183 ax-pre-mulgt0 11184 ax-pre-sup 11185 ax-addf 11186 ax-mulf 11187

This theorem depends on definitions: df-bi 206 df-an 398 df-or 847 df-3or 1089 df-3an 1090 df-tru 1545 df-fal 1555 df-ex 1783 df-nf 1787 df-sb 2069 df-mo 2535 df-eu 2564 df-clab 2711 df-cleq 2725 df-clel 2811 df-nfc 2886 df-ne 2942 df-nel 3048 df-ral 3063 df-rex 3072 df-rmo 3377 df-reu 3378 df-rab 3434 df-v 3477 df-sbc 3778 df-csb 3894 df-dif 3951 df-un 3953 df-in 3955 df-ss 3965 df-pss 3967 df-nul 4323 df-if 4529 df-pw 4604 df-sn 4629 df-pr 4631 df-tp 4633 df-op 4635 df-uni 4909 df-int 4951 df-iun 4999 df-iin 5000 df-br 5149 df-opab 5211 df-mpt 5232 df-tr 5266 df-id 5574 df-eprel 5580 df-po 5588 df-so 5589 df-fr 5631 df-se 5632 df-we 5633 df-xp 5682 df-rel 5683 df-cnv 5684 df-co 5685 df-dm 5686 df-rn 5687 df-res 5688 df-ima 5689 df-pred 6298 df-ord 6365 df-on 6366 df-lim 6367 df-suc 6368 df-iota 6493 df-fun 6543 df-fn 6544 df-f 6545 df-f1 6546 df-fo 6547 df-f1o 6548 df-fv 6549 df-isom 6550 df-riota 7362 df-ov 7409 df-oprab 7410 df-mpo 7411 df-of 7667 df-om 7853 df-1st 7972 df-2nd 7973 df-supp 8144 df-frecs 8263 df-wrecs 8294 df-recs 8368 df-rdg 8407 df-1o 8463 df-2o 8464 df-er 8700 df-map 8819 df-pm 8820 df-ixp 8889 df-en 8937 df-dom 8938 df-sdom 8939 df-fin 8940 df-fsupp 9359 df-fi 9403 df-sup 9434 df-inf 9435 df-oi 9502 df-card 9931 df-pnf 11247 df-mnf 11248 df-xr 11249 df-ltxr 11250 df-le 11251 df-sub 11443 df-neg 11444 df-div 11869 df-nn 12210 df-2 12272 df-3 12273 df-4 12274 df-5 12275 df-6 12276 df-7 12277 df-8 12278 df-9 12279 df-n0 12470 df-z 12556 df-dec 12675 df-uz 12820 df-q 12930 df-rp 12972 df-xneg 13089 df-xadd 13090 df-xmul 13091 df-ioo 13325 df-ioc 13326 df-ico 13327 df-icc 13328 df-fz 13482 df-fzo 13625 df-fl 13754 df-mod 13832 df-seq 13964 df-exp 14025 df-fac 14231 df-bc 14260 df-hash 14288 df-shft 15011 df-cj 15043 df-re 15044 df-im 15045 df-sqrt 15179 df-abs 15180 df-limsup 15412 df-clim 15429 df-rlim 15430 df-sum 15630 df-ef 16008 df-sin 16010 df-cos 16011 df-pi 16013 df-struct 17077 df-sets 17094 df-slot 17112 df-ndx 17124 df-base 17142 df-ress 17171 df-plusg 17207 df-mulr 17208 df-starv 17209 df-sca 17210 df-vsca 17211 df-ip 17212 df-tset 17213 df-ple 17214 df-ds 17216 df-unif 17217 df-hom 17218 df-cco 17219 df-rest 17365 df-topn 17366 df-0g 17384 df-gsum 17385 df-topgen 17386 df-pt 17387 df-prds 17390 df-xrs 17445 df-qtop 17450 df-imas 17451 df-xps 17453 df-mre 17527 df-mrc 17528 df-acs 17530 df-mgm 18558 df-sgrp 18607 df-mnd 18623 df-submnd 18669 df-mulg 18946 df-cntz 19176 df-cmn 19645 df-psmet 20929 df-xmet 20930 df-met 20931 df-bl 20932 df-mopn 20933 df-fbas 20934 df-fg 20935 df-cnfld 20938 df-top 22388 df-topon 22405 df-topsp 22427 df-bases 22441 df-cld 22515 df-ntr 22516 df-cls 22517 df-nei 22594 df-lp 22632 df-perf 22633 df-cn 22723 df-cnp 22724 df-haus 22811 df-tx 23058 df-hmeo 23251 df-fil 23342 df-fm 23434 df-flim 23435 df-flf 23436 df-xms 23818 df-ms 23819 df-tms 23820 df-cncf 24386 df-limc 25375 df-dv 25376 df-log 26057 df-cxp 26058

This theorem is referenced by: logsqrt 26204 dvsqrt 26240 dvcnsqrt 26242 resqrtcn 26247 sqrtcn 26248 sqrt2cxp2logb9e3 26294 efiatan 26407 efiatan2 26412 sqrtlim 26467 chpchtlim 26972 logdivsqrle 33651

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