itgsinexp - Mathbox for Glauco Siliprandi

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Theorem itgsinexp 45992

Description: A recursive formula for the integral of sin^N on the interval (0,π) . (Contributed by Glauco Siliprandi, 29-Jun-2017.)

**Hypotheses**
Ref	Expression
itgsinexp.1	⊢ 𝐼 = (𝑛 ∈ ℕ₀ ↦ ∫(0(,)π)((sin‘𝑥)↑𝑛) d𝑥)
itgsinexp.2	⊢ (𝜑 → 𝑁 ∈ (ℤ_≥‘2))

**Assertion**
Ref	Expression
itgsinexp	⊢ (𝜑 → (𝐼‘𝑁) = (((𝑁 − 1) / 𝑁) · (𝐼‘(𝑁 − 2))))

Distinct variable groups: 𝑥,𝑛,𝑁 𝜑,𝑛,𝑥 Allowed substitution hints: 𝐼(𝑥,𝑛)

**Proof of Theorem itgsinexp**
Step	Hyp	Ref	Expression
1		itgsinexp.2	. . . . . . . 8 ⊢ (𝜑 → 𝑁 ∈ (ℤ_≥‘2))
2		eluzelz 12739	. . . . . . . 8 ⊢ (𝑁 ∈ (ℤ_≥‘2) → 𝑁 ∈ ℤ)
3		zcn 12470	. . . . . . . 8 ⊢ (𝑁 ∈ ℤ → 𝑁 ∈ ℂ)
4	1, 2, 3	3syl 18	. . . . . . 7 ⊢ (𝜑 → 𝑁 ∈ ℂ)
5		1cnd 11104	. . . . . . 7 ⊢ (𝜑 → 1 ∈ ℂ)
6	4, 5	npcand 11473	. . . . . 6 ⊢ (𝜑 → ((𝑁 − 1) + 1) = 𝑁)
7	6	eqcomd 2737	. . . . 5 ⊢ (𝜑 → 𝑁 = ((𝑁 − 1) + 1))
8	7	oveq1d 7361	. . . 4 ⊢ (𝜑 → (𝑁 · (𝐼‘𝑁)) = (((𝑁 − 1) + 1) · (𝐼‘𝑁)))
9		uz2m1nn 12818	. . . . . . 7 ⊢ (𝑁 ∈ (ℤ_≥‘2) → (𝑁 − 1) ∈ ℕ)
10	1, 9	syl 17	. . . . . 6 ⊢ (𝜑 → (𝑁 − 1) ∈ ℕ)
11	10	nncnd 12138	. . . . 5 ⊢ (𝜑 → (𝑁 − 1) ∈ ℂ)
12		itgsinexp.1	. . . . . . . 8 ⊢ 𝐼 = (𝑛 ∈ ℕ₀ ↦ ∫(0(,)π)((sin‘𝑥)↑𝑛) d𝑥)
13	12	a1i 11	. . . . . . 7 ⊢ (𝜑 → 𝐼 = (𝑛 ∈ ℕ₀ ↦ ∫(0(,)π)((sin‘𝑥)↑𝑛) d𝑥))
14		oveq2 7354	. . . . . . . . 9 ⊢ (𝑛 = 𝑁 → ((sin‘𝑥)↑𝑛) = ((sin‘𝑥)↑𝑁))
15	14	ad2antlr 727	. . . . . . . 8 ⊢ (((𝜑 ∧ 𝑛 = 𝑁) ∧ 𝑥 ∈ (0(,)π)) → ((sin‘𝑥)↑𝑛) = ((sin‘𝑥)↑𝑁))
16	15	itgeq2dv 25708	. . . . . . 7 ⊢ ((𝜑 ∧ 𝑛 = 𝑁) → ∫(0(,)π)((sin‘𝑥)↑𝑛) d𝑥 = ∫(0(,)π)((sin‘𝑥)↑𝑁) d𝑥)
17		2cnd 12200	. . . . . . . . 9 ⊢ (𝜑 → 2 ∈ ℂ)
18		npcan 11366	. . . . . . . . . 10 ⊢ ((𝑁 ∈ ℂ ∧ 2 ∈ ℂ) → ((𝑁 − 2) + 2) = 𝑁)
19	18	eqcomd 2737	. . . . . . . . 9 ⊢ ((𝑁 ∈ ℂ ∧ 2 ∈ ℂ) → 𝑁 = ((𝑁 − 2) + 2))
20	4, 17, 19	syl2anc 584	. . . . . . . 8 ⊢ (𝜑 → 𝑁 = ((𝑁 − 2) + 2))
21		uznn0sub 12768	. . . . . . . . . 10 ⊢ (𝑁 ∈ (ℤ_≥‘2) → (𝑁 − 2) ∈ ℕ₀)
22	1, 21	syl 17	. . . . . . . . 9 ⊢ (𝜑 → (𝑁 − 2) ∈ ℕ₀)
23		2nn0 12395	. . . . . . . . . 10 ⊢ 2 ∈ ℕ₀
24	23	a1i 11	. . . . . . . . 9 ⊢ (𝜑 → 2 ∈ ℕ₀)
25	22, 24	nn0addcld 12443	. . . . . . . 8 ⊢ (𝜑 → ((𝑁 − 2) + 2) ∈ ℕ₀)
26	20, 25	eqeltrd 2831	. . . . . . 7 ⊢ (𝜑 → 𝑁 ∈ ℕ₀)
27		itgex 25696	. . . . . . . 8 ⊢ ∫(0(,)π)((sin‘𝑥)↑𝑁) d𝑥 ∈ V
28	27	a1i 11	. . . . . . 7 ⊢ (𝜑 → ∫(0(,)π)((sin‘𝑥)↑𝑁) d𝑥 ∈ V)
29	13, 16, 26, 28	fvmptd 6936	. . . . . 6 ⊢ (𝜑 → (𝐼‘𝑁) = ∫(0(,)π)((sin‘𝑥)↑𝑁) d𝑥)
30		ioosscn 13305	. . . . . . . . . . 11 ⊢ (0(,)π) ⊆ ℂ
31	30	sseli 3930	. . . . . . . . . 10 ⊢ (𝑥 ∈ (0(,)π) → 𝑥 ∈ ℂ)
32	31	sincld 16036	. . . . . . . . 9 ⊢ (𝑥 ∈ (0(,)π) → (sin‘𝑥) ∈ ℂ)
33	32	adantl 481	. . . . . . . 8 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → (sin‘𝑥) ∈ ℂ)
34	26	adantr 480	. . . . . . . 8 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → 𝑁 ∈ ℕ₀)
35	33, 34	expcld 14050	. . . . . . 7 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → ((sin‘𝑥)↑𝑁) ∈ ℂ)
36		ioossicc 13330	. . . . . . . . 9 ⊢ (0(,)π) ⊆ (0[,]π)
37	36	a1i 11	. . . . . . . 8 ⊢ (𝜑 → (0(,)π) ⊆ (0[,]π))
38		ioombl 25491	. . . . . . . . 9 ⊢ (0(,)π) ∈ dom vol
39	38	a1i 11	. . . . . . . 8 ⊢ (𝜑 → (0(,)π) ∈ dom vol)
40		0re 11111	. . . . . . . . . . . . . 14 ⊢ 0 ∈ ℝ
41		pire 26391	. . . . . . . . . . . . . 14 ⊢ π ∈ ℝ
42		iccssre 13326	. . . . . . . . . . . . . 14 ⊢ ((0 ∈ ℝ ∧ π ∈ ℝ) → (0[,]π) ⊆ ℝ)
43	40, 41, 42	mp2an 692	. . . . . . . . . . . . 13 ⊢ (0[,]π) ⊆ ℝ
44		ax-resscn 11060	. . . . . . . . . . . . 13 ⊢ ℝ ⊆ ℂ
45	43, 44	sstri 3944	. . . . . . . . . . . 12 ⊢ (0[,]π) ⊆ ℂ
46	45	sseli 3930	. . . . . . . . . . 11 ⊢ (𝑥 ∈ (0[,]π) → 𝑥 ∈ ℂ)
47	46	sincld 16036	. . . . . . . . . 10 ⊢ (𝑥 ∈ (0[,]π) → (sin‘𝑥) ∈ ℂ)
48	47	adantl 481	. . . . . . . . 9 ⊢ ((𝜑 ∧ 𝑥 ∈ (0[,]π)) → (sin‘𝑥) ∈ ℂ)
49	26	adantr 480	. . . . . . . . 9 ⊢ ((𝜑 ∧ 𝑥 ∈ (0[,]π)) → 𝑁 ∈ ℕ₀)
50	48, 49	expcld 14050	. . . . . . . 8 ⊢ ((𝜑 ∧ 𝑥 ∈ (0[,]π)) → ((sin‘𝑥)↑𝑁) ∈ ℂ)
51	40	a1i 11	. . . . . . . . 9 ⊢ (𝜑 → 0 ∈ ℝ)
52	41	a1i 11	. . . . . . . . 9 ⊢ (𝜑 → π ∈ ℝ)
53	46	adantl 481	. . . . . . . . . . . . 13 ⊢ ((𝜑 ∧ 𝑥 ∈ (0[,]π)) → 𝑥 ∈ ℂ)
54		eqid 2731	. . . . . . . . . . . . . 14 ⊢ (𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑𝑁)) = (𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑𝑁))
55	54	fvmpt2 6940	. . . . . . . . . . . . 13 ⊢ ((𝑥 ∈ ℂ ∧ ((sin‘𝑥)↑𝑁) ∈ ℂ) → ((𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑𝑁))‘𝑥) = ((sin‘𝑥)↑𝑁))
56	53, 50, 55	syl2anc 584	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑥 ∈ (0[,]π)) → ((𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑𝑁))‘𝑥) = ((sin‘𝑥)↑𝑁))
57	56	eqcomd 2737	. . . . . . . . . . 11 ⊢ ((𝜑 ∧ 𝑥 ∈ (0[,]π)) → ((sin‘𝑥)↑𝑁) = ((𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑𝑁))‘𝑥))
58	57	mpteq2dva 5184	. . . . . . . . . 10 ⊢ (𝜑 → (𝑥 ∈ (0[,]π) ↦ ((sin‘𝑥)↑𝑁)) = (𝑥 ∈ (0[,]π) ↦ ((𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑𝑁))‘𝑥)))
59		nfmpt1 5190	. . . . . . . . . . 11 ⊢ Ⅎ𝑥(𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑𝑁))
60		nfcv 2894	. . . . . . . . . . . 12 ⊢ Ⅎ𝑥sin
61		sincn 26379	. . . . . . . . . . . . 13 ⊢ sin ∈ (ℂ–cn→ℂ)
62	61	a1i 11	. . . . . . . . . . . 12 ⊢ (𝜑 → sin ∈ (ℂ–cn→ℂ))
63	60, 62, 26	expcnfg 45630	. . . . . . . . . . 11 ⊢ (𝜑 → (𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑𝑁)) ∈ (ℂ–cn→ℂ))
64	45	a1i 11	. . . . . . . . . . 11 ⊢ (𝜑 → (0[,]π) ⊆ ℂ)
65	59, 63, 64	cncfmptss 45626	. . . . . . . . . 10 ⊢ (𝜑 → (𝑥 ∈ (0[,]π) ↦ ((𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑𝑁))‘𝑥)) ∈ ((0[,]π)–cn→ℂ))
66	58, 65	eqeltrd 2831	. . . . . . . . 9 ⊢ (𝜑 → (𝑥 ∈ (0[,]π) ↦ ((sin‘𝑥)↑𝑁)) ∈ ((0[,]π)–cn→ℂ))
67		cniccibl 25767	. . . . . . . . 9 ⊢ ((0 ∈ ℝ ∧ π ∈ ℝ ∧ (𝑥 ∈ (0[,]π) ↦ ((sin‘𝑥)↑𝑁)) ∈ ((0[,]π)–cn→ℂ)) → (𝑥 ∈ (0[,]π) ↦ ((sin‘𝑥)↑𝑁)) ∈ 𝐿¹)
68	51, 52, 66, 67	syl3anc 1373	. . . . . . . 8 ⊢ (𝜑 → (𝑥 ∈ (0[,]π) ↦ ((sin‘𝑥)↑𝑁)) ∈ 𝐿¹)
69	37, 39, 50, 68	iblss 25731	. . . . . . 7 ⊢ (𝜑 → (𝑥 ∈ (0(,)π) ↦ ((sin‘𝑥)↑𝑁)) ∈ 𝐿¹)
70	35, 69	itgcl 25710	. . . . . 6 ⊢ (𝜑 → ∫(0(,)π)((sin‘𝑥)↑𝑁) d𝑥 ∈ ℂ)
71	29, 70	eqeltrd 2831	. . . . 5 ⊢ (𝜑 → (𝐼‘𝑁) ∈ ℂ)
72	11, 71	adddirp1d 11135	. . . 4 ⊢ (𝜑 → (((𝑁 − 1) + 1) · (𝐼‘𝑁)) = (((𝑁 − 1) · (𝐼‘𝑁)) + (𝐼‘𝑁)))
73		eluz2b2 12816	. . . . . . . . . . . 12 ⊢ (𝑁 ∈ (ℤ_≥‘2) ↔ (𝑁 ∈ ℕ ∧ 1 < 𝑁))
74	1, 73	sylib 218	. . . . . . . . . . 11 ⊢ (𝜑 → (𝑁 ∈ ℕ ∧ 1 < 𝑁))
75	74	simpld 494	. . . . . . . . . 10 ⊢ (𝜑 → 𝑁 ∈ ℕ)
76		expm1t 13994	. . . . . . . . . 10 ⊢ (((sin‘𝑥) ∈ ℂ ∧ 𝑁 ∈ ℕ) → ((sin‘𝑥)↑𝑁) = (((sin‘𝑥)↑(𝑁 − 1)) · (sin‘𝑥)))
77	32, 75, 76	syl2anr 597	. . . . . . . . 9 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → ((sin‘𝑥)↑𝑁) = (((sin‘𝑥)↑(𝑁 − 1)) · (sin‘𝑥)))
78	77	itgeq2dv 25708	. . . . . . . 8 ⊢ (𝜑 → ∫(0(,)π)((sin‘𝑥)↑𝑁) d𝑥 = ∫(0(,)π)(((sin‘𝑥)↑(𝑁 − 1)) · (sin‘𝑥)) d𝑥)
79		eqid 2731	. . . . . . . . . 10 ⊢ (𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑(𝑁 − 1))) = (𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑(𝑁 − 1)))
80		eqid 2731	. . . . . . . . . 10 ⊢ (𝑥 ∈ ℂ ↦ -(cos‘𝑥)) = (𝑥 ∈ ℂ ↦ -(cos‘𝑥))
81		eqid 2731	. . . . . . . . . 10 ⊢ (𝑥 ∈ ℂ ↦ (((𝑁 − 1) · ((sin‘𝑥)↑((𝑁 − 1) − 1))) · (cos‘𝑥))) = (𝑥 ∈ ℂ ↦ (((𝑁 − 1) · ((sin‘𝑥)↑((𝑁 − 1) − 1))) · (cos‘𝑥)))
82		eqid 2731	. . . . . . . . . 10 ⊢ (𝑥 ∈ ℂ ↦ (((sin‘𝑥)↑(𝑁 − 1)) · (sin‘𝑥))) = (𝑥 ∈ ℂ ↦ (((sin‘𝑥)↑(𝑁 − 1)) · (sin‘𝑥)))
83		eqid 2731	. . . . . . . . . 10 ⊢ (𝑥 ∈ ℂ ↦ ((((𝑁 − 1) · ((sin‘𝑥)↑((𝑁 − 1) − 1))) · (cos‘𝑥)) · -(cos‘𝑥))) = (𝑥 ∈ ℂ ↦ ((((𝑁 − 1) · ((sin‘𝑥)↑((𝑁 − 1) − 1))) · (cos‘𝑥)) · -(cos‘𝑥)))
84		eqid 2731	. . . . . . . . . 10 ⊢ (𝑥 ∈ ℂ ↦ (((cos‘𝑥)↑2) · ((sin‘𝑥)↑((𝑁 − 1) − 1)))) = (𝑥 ∈ ℂ ↦ (((cos‘𝑥)↑2) · ((sin‘𝑥)↑((𝑁 − 1) − 1))))
85	79, 80, 81, 82, 83, 84, 10	itgsinexplem1 45991	. . . . . . . . 9 ⊢ (𝜑 → ∫(0(,)π)(((sin‘𝑥)↑(𝑁 − 1)) · (sin‘𝑥)) d𝑥 = ((𝑁 − 1) · ∫(0(,)π)(((cos‘𝑥)↑2) · ((sin‘𝑥)↑((𝑁 − 1) − 1))) d𝑥))
86	4, 5, 5	subsub4d 11500	. . . . . . . . . . . . . . 15 ⊢ (𝜑 → ((𝑁 − 1) − 1) = (𝑁 − (1 + 1)))
87		1p1e2 12242	. . . . . . . . . . . . . . . . 17 ⊢ (1 + 1) = 2
88	87	a1i 11	. . . . . . . . . . . . . . . 16 ⊢ (𝜑 → (1 + 1) = 2)
89	88	oveq2d 7362	. . . . . . . . . . . . . . 15 ⊢ (𝜑 → (𝑁 − (1 + 1)) = (𝑁 − 2))
90	86, 89	eqtrd 2766	. . . . . . . . . . . . . 14 ⊢ (𝜑 → ((𝑁 − 1) − 1) = (𝑁 − 2))
91	90	adantr 480	. . . . . . . . . . . . 13 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → ((𝑁 − 1) − 1) = (𝑁 − 2))
92	91	oveq2d 7362	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → ((sin‘𝑥)↑((𝑁 − 1) − 1)) = ((sin‘𝑥)↑(𝑁 − 2)))
93	92	oveq2d 7362	. . . . . . . . . . 11 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → (((cos‘𝑥)↑2) · ((sin‘𝑥)↑((𝑁 − 1) − 1))) = (((cos‘𝑥)↑2) · ((sin‘𝑥)↑(𝑁 − 2))))
94	93	itgeq2dv 25708	. . . . . . . . . 10 ⊢ (𝜑 → ∫(0(,)π)(((cos‘𝑥)↑2) · ((sin‘𝑥)↑((𝑁 − 1) − 1))) d𝑥 = ∫(0(,)π)(((cos‘𝑥)↑2) · ((sin‘𝑥)↑(𝑁 − 2))) d𝑥)
95	94	oveq2d 7362	. . . . . . . . 9 ⊢ (𝜑 → ((𝑁 − 1) · ∫(0(,)π)(((cos‘𝑥)↑2) · ((sin‘𝑥)↑((𝑁 − 1) − 1))) d𝑥) = ((𝑁 − 1) · ∫(0(,)π)(((cos‘𝑥)↑2) · ((sin‘𝑥)↑(𝑁 − 2))) d𝑥))
96		sincossq 16082	. . . . . . . . . . . . . . . . 17 ⊢ (𝑥 ∈ ℂ → (((sin‘𝑥)↑2) + ((cos‘𝑥)↑2)) = 1)
97		1cnd 11104	. . . . . . . . . . . . . . . . . 18 ⊢ (𝑥 ∈ ℂ → 1 ∈ ℂ)
98		sincl 16032	. . . . . . . . . . . . . . . . . . 19 ⊢ (𝑥 ∈ ℂ → (sin‘𝑥) ∈ ℂ)
99	98	sqcld 14048	. . . . . . . . . . . . . . . . . 18 ⊢ (𝑥 ∈ ℂ → ((sin‘𝑥)↑2) ∈ ℂ)
100		coscl 16033	. . . . . . . . . . . . . . . . . . 19 ⊢ (𝑥 ∈ ℂ → (cos‘𝑥) ∈ ℂ)
101	100	sqcld 14048	. . . . . . . . . . . . . . . . . 18 ⊢ (𝑥 ∈ ℂ → ((cos‘𝑥)↑2) ∈ ℂ)
102	97, 99, 101	subaddd 11487	. . . . . . . . . . . . . . . . 17 ⊢ (𝑥 ∈ ℂ → ((1 − ((sin‘𝑥)↑2)) = ((cos‘𝑥)↑2) ↔ (((sin‘𝑥)↑2) + ((cos‘𝑥)↑2)) = 1))
103	96, 102	mpbird 257	. . . . . . . . . . . . . . . 16 ⊢ (𝑥 ∈ ℂ → (1 − ((sin‘𝑥)↑2)) = ((cos‘𝑥)↑2))
104	103	eqcomd 2737	. . . . . . . . . . . . . . 15 ⊢ (𝑥 ∈ ℂ → ((cos‘𝑥)↑2) = (1 − ((sin‘𝑥)↑2)))
105	31, 104	syl 17	. . . . . . . . . . . . . 14 ⊢ (𝑥 ∈ (0(,)π) → ((cos‘𝑥)↑2) = (1 − ((sin‘𝑥)↑2)))
106	105	oveq1d 7361	. . . . . . . . . . . . 13 ⊢ (𝑥 ∈ (0(,)π) → (((cos‘𝑥)↑2) · ((sin‘𝑥)↑(𝑁 − 2))) = ((1 − ((sin‘𝑥)↑2)) · ((sin‘𝑥)↑(𝑁 − 2))))
107	106	adantl 481	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → (((cos‘𝑥)↑2) · ((sin‘𝑥)↑(𝑁 − 2))) = ((1 − ((sin‘𝑥)↑2)) · ((sin‘𝑥)↑(𝑁 − 2))))
108	107	itgeq2dv 25708	. . . . . . . . . . 11 ⊢ (𝜑 → ∫(0(,)π)(((cos‘𝑥)↑2) · ((sin‘𝑥)↑(𝑁 − 2))) d𝑥 = ∫(0(,)π)((1 − ((sin‘𝑥)↑2)) · ((sin‘𝑥)↑(𝑁 − 2))) d𝑥)
109		1cnd 11104	. . . . . . . . . . . . . 14 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → 1 ∈ ℂ)
110	32	sqcld 14048	. . . . . . . . . . . . . . 15 ⊢ (𝑥 ∈ (0(,)π) → ((sin‘𝑥)↑2) ∈ ℂ)
111	110	adantl 481	. . . . . . . . . . . . . 14 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → ((sin‘𝑥)↑2) ∈ ℂ)
112	90	eqcomd 2737	. . . . . . . . . . . . . . . . 17 ⊢ (𝜑 → (𝑁 − 2) = ((𝑁 − 1) − 1))
113		nnm1nn0 12419	. . . . . . . . . . . . . . . . . 18 ⊢ ((𝑁 − 1) ∈ ℕ → ((𝑁 − 1) − 1) ∈ ℕ₀)
114	10, 113	syl 17	. . . . . . . . . . . . . . . . 17 ⊢ (𝜑 → ((𝑁 − 1) − 1) ∈ ℕ₀)
115	112, 114	eqeltrd 2831	. . . . . . . . . . . . . . . 16 ⊢ (𝜑 → (𝑁 − 2) ∈ ℕ₀)
116	115	adantr 480	. . . . . . . . . . . . . . 15 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → (𝑁 − 2) ∈ ℕ₀)
117	33, 116	expcld 14050	. . . . . . . . . . . . . 14 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → ((sin‘𝑥)↑(𝑁 − 2)) ∈ ℂ)
118	109, 111, 117	subdird 11571	. . . . . . . . . . . . 13 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → ((1 − ((sin‘𝑥)↑2)) · ((sin‘𝑥)↑(𝑁 − 2))) = ((1 · ((sin‘𝑥)↑(𝑁 − 2))) − (((sin‘𝑥)↑2) · ((sin‘𝑥)↑(𝑁 − 2)))))
119	117	mullidd 11127	. . . . . . . . . . . . . 14 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → (1 · ((sin‘𝑥)↑(𝑁 − 2))) = ((sin‘𝑥)↑(𝑁 − 2)))
120	23	a1i 11	. . . . . . . . . . . . . . . 16 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → 2 ∈ ℕ₀)
121	33, 116, 120	expaddd 14052	. . . . . . . . . . . . . . 15 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → ((sin‘𝑥)↑(2 + (𝑁 − 2))) = (((sin‘𝑥)↑2) · ((sin‘𝑥)↑(𝑁 − 2))))
122	17, 4	pncan3d 11472	. . . . . . . . . . . . . . . . 17 ⊢ (𝜑 → (2 + (𝑁 − 2)) = 𝑁)
123	122	oveq2d 7362	. . . . . . . . . . . . . . . 16 ⊢ (𝜑 → ((sin‘𝑥)↑(2 + (𝑁 − 2))) = ((sin‘𝑥)↑𝑁))
124	123	adantr 480	. . . . . . . . . . . . . . 15 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → ((sin‘𝑥)↑(2 + (𝑁 − 2))) = ((sin‘𝑥)↑𝑁))
125	121, 124	eqtr3d 2768	. . . . . . . . . . . . . 14 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → (((sin‘𝑥)↑2) · ((sin‘𝑥)↑(𝑁 − 2))) = ((sin‘𝑥)↑𝑁))
126	119, 125	oveq12d 7364	. . . . . . . . . . . . 13 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → ((1 · ((sin‘𝑥)↑(𝑁 − 2))) − (((sin‘𝑥)↑2) · ((sin‘𝑥)↑(𝑁 − 2)))) = (((sin‘𝑥)↑(𝑁 − 2)) − ((sin‘𝑥)↑𝑁)))
127	118, 126	eqtrd 2766	. . . . . . . . . . . 12 ⊢ ((𝜑 ∧ 𝑥 ∈ (0(,)π)) → ((1 − ((sin‘𝑥)↑2)) · ((sin‘𝑥)↑(𝑁 − 2))) = (((sin‘𝑥)↑(𝑁 − 2)) − ((sin‘𝑥)↑𝑁)))
128	127	itgeq2dv 25708	. . . . . . . . . . 11 ⊢ (𝜑 → ∫(0(,)π)((1 − ((sin‘𝑥)↑2)) · ((sin‘𝑥)↑(𝑁 − 2))) d𝑥 = ∫(0(,)π)(((sin‘𝑥)↑(𝑁 − 2)) − ((sin‘𝑥)↑𝑁)) d𝑥)
129	115	adantr 480	. . . . . . . . . . . . . 14 ⊢ ((𝜑 ∧ 𝑥 ∈ (0[,]π)) → (𝑁 − 2) ∈ ℕ₀)
130	48, 129	expcld 14050	. . . . . . . . . . . . 13 ⊢ ((𝜑 ∧ 𝑥 ∈ (0[,]π)) → ((sin‘𝑥)↑(𝑁 − 2)) ∈ ℂ)
131		eqid 2731	. . . . . . . . . . . . . . . . . . 19 ⊢ (𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑(𝑁 − 2))) = (𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑(𝑁 − 2)))
132	131	fvmpt2 6940	. . . . . . . . . . . . . . . . . 18 ⊢ ((𝑥 ∈ ℂ ∧ ((sin‘𝑥)↑(𝑁 − 2)) ∈ ℂ) → ((𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑(𝑁 − 2)))‘𝑥) = ((sin‘𝑥)↑(𝑁 − 2)))
133	53, 130, 132	syl2anc 584	. . . . . . . . . . . . . . . . 17 ⊢ ((𝜑 ∧ 𝑥 ∈ (0[,]π)) → ((𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑(𝑁 − 2)))‘𝑥) = ((sin‘𝑥)↑(𝑁 − 2)))
134	133	eqcomd 2737	. . . . . . . . . . . . . . . 16 ⊢ ((𝜑 ∧ 𝑥 ∈ (0[,]π)) → ((sin‘𝑥)↑(𝑁 − 2)) = ((𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑(𝑁 − 2)))‘𝑥))
135	134	mpteq2dva 5184	. . . . . . . . . . . . . . 15 ⊢ (𝜑 → (𝑥 ∈ (0[,]π) ↦ ((sin‘𝑥)↑(𝑁 − 2))) = (𝑥 ∈ (0[,]π) ↦ ((𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑(𝑁 − 2)))‘𝑥)))
136		nfmpt1 5190	. . . . . . . . . . . . . . . 16 ⊢ Ⅎ𝑥(𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑(𝑁 − 2)))
137	60, 62, 115	expcnfg 45630	. . . . . . . . . . . . . . . 16 ⊢ (𝜑 → (𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑(𝑁 − 2))) ∈ (ℂ–cn→ℂ))
138	136, 137, 64	cncfmptss 45626	. . . . . . . . . . . . . . 15 ⊢ (𝜑 → (𝑥 ∈ (0[,]π) ↦ ((𝑥 ∈ ℂ ↦ ((sin‘𝑥)↑(𝑁 − 2)))‘𝑥)) ∈ ((0[,]π)–cn→ℂ))
139	135, 138	eqeltrd 2831	. . . . . . . . . . . . . 14 ⊢ (𝜑 → (𝑥 ∈ (0[,]π) ↦ ((sin‘𝑥)↑(𝑁 − 2))) ∈ ((0[,]π)–cn→ℂ))
140		cniccibl 25767	. . . . . . . . . . . . . 14 ⊢ ((0 ∈ ℝ ∧ π ∈ ℝ ∧ (𝑥 ∈ (0[,]π) ↦ ((sin‘𝑥)↑(𝑁 − 2))) ∈ ((0[,]π)–cn→ℂ)) → (𝑥 ∈ (0[,]π) ↦ ((sin‘𝑥)↑(𝑁 − 2))) ∈ 𝐿¹)
141	51, 52, 139, 140	syl3anc 1373	. . . . . . . . . . . . 13 ⊢ (𝜑 → (𝑥 ∈ (0[,]π) ↦ ((sin‘𝑥)↑(𝑁 − 2))) ∈ 𝐿¹)
142	37, 39, 130, 141	iblss 25731	. . . . . . . . . . . 12 ⊢ (𝜑 → (𝑥 ∈ (0(,)π) ↦ ((sin‘𝑥)↑(𝑁 − 2))) ∈ 𝐿¹)
143	117, 142, 35, 69	itgsub 25752	. . . . . . . . . . 11 ⊢ (𝜑 → ∫(0(,)π)(((sin‘𝑥)↑(𝑁 − 2)) − ((sin‘𝑥)↑𝑁)) d𝑥 = (∫(0(,)π)((sin‘𝑥)↑(𝑁 − 2)) d𝑥 − ∫(0(,)π)((sin‘𝑥)↑𝑁) d𝑥))
144	108, 128, 143	3eqtrd 2770	. . . . . . . . . 10 ⊢ (𝜑 → ∫(0(,)π)(((cos‘𝑥)↑2) · ((sin‘𝑥)↑(𝑁 − 2))) d𝑥 = (∫(0(,)π)((sin‘𝑥)↑(𝑁 − 2)) d𝑥 − ∫(0(,)π)((sin‘𝑥)↑𝑁) d𝑥))
145	144	oveq2d 7362	. . . . . . . . 9 ⊢ (𝜑 → ((𝑁 − 1) · ∫(0(,)π)(((cos‘𝑥)↑2) · ((sin‘𝑥)↑(𝑁 − 2))) d𝑥) = ((𝑁 − 1) · (∫(0(,)π)((sin‘𝑥)↑(𝑁 − 2)) d𝑥 − ∫(0(,)π)((sin‘𝑥)↑𝑁) d𝑥)))
146	85, 95, 145	3eqtrd 2770	. . . . . . . 8 ⊢ (𝜑 → ∫(0(,)π)(((sin‘𝑥)↑(𝑁 − 1)) · (sin‘𝑥)) d𝑥 = ((𝑁 − 1) · (∫(0(,)π)((sin‘𝑥)↑(𝑁 − 2)) d𝑥 − ∫(0(,)π)((sin‘𝑥)↑𝑁) d𝑥)))
147	29, 78, 146	3eqtrd 2770	. . . . . . 7 ⊢ (𝜑 → (𝐼‘𝑁) = ((𝑁 − 1) · (∫(0(,)π)((sin‘𝑥)↑(𝑁 − 2)) d𝑥 − ∫(0(,)π)((sin‘𝑥)↑𝑁) d𝑥)))
148		oveq2 7354	. . . . . . . . . . . 12 ⊢ (𝑛 = (𝑁 − 2) → ((sin‘𝑥)↑𝑛) = ((sin‘𝑥)↑(𝑁 − 2)))
149	148	adantr 480	. . . . . . . . . . 11 ⊢ ((𝑛 = (𝑁 − 2) ∧ 𝑥 ∈ (0(,)π)) → ((sin‘𝑥)↑𝑛) = ((sin‘𝑥)↑(𝑁 − 2)))
150	149	itgeq2dv 25708	. . . . . . . . . 10 ⊢ (𝑛 = (𝑁 − 2) → ∫(0(,)π)((sin‘𝑥)↑𝑛) d𝑥 = ∫(0(,)π)((sin‘𝑥)↑(𝑁 − 2)) d𝑥)
151		itgex 25696	. . . . . . . . . . 11 ⊢ ∫(0(,)π)((sin‘𝑥)↑(𝑁 − 2)) d𝑥 ∈ V
152	151	a1i 11	. . . . . . . . . 10 ⊢ (𝜑 → ∫(0(,)π)((sin‘𝑥)↑(𝑁 − 2)) d𝑥 ∈ V)
153	12, 150, 115, 152	fvmptd3 6952	. . . . . . . . 9 ⊢ (𝜑 → (𝐼‘(𝑁 − 2)) = ∫(0(,)π)((sin‘𝑥)↑(𝑁 − 2)) d𝑥)
154	153, 29	oveq12d 7364	. . . . . . . 8 ⊢ (𝜑 → ((𝐼‘(𝑁 − 2)) − (𝐼‘𝑁)) = (∫(0(,)π)((sin‘𝑥)↑(𝑁 − 2)) d𝑥 − ∫(0(,)π)((sin‘𝑥)↑𝑁) d𝑥))
155	154	oveq2d 7362	. . . . . . 7 ⊢ (𝜑 → ((𝑁 − 1) · ((𝐼‘(𝑁 − 2)) − (𝐼‘𝑁))) = ((𝑁 − 1) · (∫(0(,)π)((sin‘𝑥)↑(𝑁 − 2)) d𝑥 − ∫(0(,)π)((sin‘𝑥)↑𝑁) d𝑥)))
156	117, 142	itgcl 25710	. . . . . . . . 9 ⊢ (𝜑 → ∫(0(,)π)((sin‘𝑥)↑(𝑁 − 2)) d𝑥 ∈ ℂ)
157	153, 156	eqeltrd 2831	. . . . . . . 8 ⊢ (𝜑 → (𝐼‘(𝑁 − 2)) ∈ ℂ)
158	11, 157, 71	subdid 11570	. . . . . . 7 ⊢ (𝜑 → ((𝑁 − 1) · ((𝐼‘(𝑁 − 2)) − (𝐼‘𝑁))) = (((𝑁 − 1) · (𝐼‘(𝑁 − 2))) − ((𝑁 − 1) · (𝐼‘𝑁))))
159	147, 155, 158	3eqtr2d 2772	. . . . . 6 ⊢ (𝜑 → (𝐼‘𝑁) = (((𝑁 − 1) · (𝐼‘(𝑁 − 2))) − ((𝑁 − 1) · (𝐼‘𝑁))))
160	159	eqcomd 2737	. . . . 5 ⊢ (𝜑 → (((𝑁 − 1) · (𝐼‘(𝑁 − 2))) − ((𝑁 − 1) · (𝐼‘𝑁))) = (𝐼‘𝑁))
161	11, 157	mulcld 11129	. . . . . 6 ⊢ (𝜑 → ((𝑁 − 1) · (𝐼‘(𝑁 − 2))) ∈ ℂ)
162	11, 71	mulcld 11129	. . . . . 6 ⊢ (𝜑 → ((𝑁 − 1) · (𝐼‘𝑁)) ∈ ℂ)
163	161, 162, 71	subaddd 11487	. . . . 5 ⊢ (𝜑 → ((((𝑁 − 1) · (𝐼‘(𝑁 − 2))) − ((𝑁 − 1) · (𝐼‘𝑁))) = (𝐼‘𝑁) ↔ (((𝑁 − 1) · (𝐼‘𝑁)) + (𝐼‘𝑁)) = ((𝑁 − 1) · (𝐼‘(𝑁 − 2)))))
164	160, 163	mpbid 232	. . . 4 ⊢ (𝜑 → (((𝑁 − 1) · (𝐼‘𝑁)) + (𝐼‘𝑁)) = ((𝑁 − 1) · (𝐼‘(𝑁 − 2))))
165	8, 72, 164	3eqtrd 2770	. . 3 ⊢ (𝜑 → (𝑁 · (𝐼‘𝑁)) = ((𝑁 − 1) · (𝐼‘(𝑁 − 2))))
166	165	oveq1d 7361	. 2 ⊢ (𝜑 → ((𝑁 · (𝐼‘𝑁)) / 𝑁) = (((𝑁 − 1) · (𝐼‘(𝑁 − 2))) / 𝑁))
167	75	nnne0d 12172	. . 3 ⊢ (𝜑 → 𝑁 ≠ 0)
168	71, 4, 167	divcan3d 11899	. 2 ⊢ (𝜑 → ((𝑁 · (𝐼‘𝑁)) / 𝑁) = (𝐼‘𝑁))
169	11, 157, 4, 167	div23d 11931	. 2 ⊢ (𝜑 → (((𝑁 − 1) · (𝐼‘(𝑁 − 2))) / 𝑁) = (((𝑁 − 1) / 𝑁) · (𝐼‘(𝑁 − 2))))
170	166, 168, 169	3eqtr3d 2774	1 ⊢ (𝜑 → (𝐼‘𝑁) = (((𝑁 − 1) / 𝑁) · (𝐼‘(𝑁 − 2))))

Colors of variables: wff setvar class

Syntax hints: → wi 4 ∧ wa 395 = wceq 1541 ∈ wcel 2111 Vcvv 3436 ⊆ wss 3902 class class class wbr 5091 ↦ cmpt 5172 dom cdm 5616 ‘cfv 6481 (class class class)co 7346 ℂcc 11001 ℝcr 11002 0cc0 11003 1c1 11004 + caddc 11006 · cmul 11008 < clt 11143 − cmin 11341 -cneg 11342 / cdiv 11771 ℕcn 12122 2c2 12177 ℕ₀cn0 12378 ℤcz 12465 ℤ_≥cuz 12729 (,)cioo 13242 [,]cicc 13245 ↑cexp 13965 sincsin 15967 cosccos 15968 πcpi 15970 –cn→ccncf 24794 volcvol 25389 𝐿¹cibl 25543 ∫citg 25544

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1796 ax-4 1810 ax-5 1911 ax-6 1968 ax-7 2009 ax-8 2113 ax-9 2121 ax-10 2144 ax-11 2160 ax-12 2180 ax-ext 2703 ax-rep 5217 ax-sep 5234 ax-nul 5244 ax-pow 5303 ax-pr 5370 ax-un 7668 ax-inf2 9531 ax-cc 10323 ax-cnex 11059 ax-resscn 11060 ax-1cn 11061 ax-icn 11062 ax-addcl 11063 ax-addrcl 11064 ax-mulcl 11065 ax-mulrcl 11066 ax-mulcom 11067 ax-addass 11068 ax-mulass 11069 ax-distr 11070 ax-i2m1 11071 ax-1ne0 11072 ax-1rid 11073 ax-rnegex 11074 ax-rrecex 11075 ax-cnre 11076 ax-pre-lttri 11077 ax-pre-lttrn 11078 ax-pre-ltadd 11079 ax-pre-mulgt0 11080 ax-pre-sup 11081 ax-addf 11082

This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3or 1087 df-3an 1088 df-tru 1544 df-fal 1554 df-ex 1781 df-nf 1785 df-sb 2068 df-mo 2535 df-eu 2564 df-clab 2710 df-cleq 2723 df-clel 2806 df-nfc 2881 df-ne 2929 df-nel 3033 df-ral 3048 df-rex 3057 df-rmo 3346 df-reu 3347 df-rab 3396 df-v 3438 df-sbc 3742 df-csb 3851 df-dif 3905 df-un 3907 df-in 3909 df-ss 3919 df-pss 3922 df-symdif 4203 df-nul 4284 df-if 4476 df-pw 4552 df-sn 4577 df-pr 4579 df-tp 4581 df-op 4583 df-uni 4860 df-int 4898 df-iun 4943 df-iin 4944 df-disj 5059 df-br 5092 df-opab 5154 df-mpt 5173 df-tr 5199 df-id 5511 df-eprel 5516 df-po 5524 df-so 5525 df-fr 5569 df-se 5570 df-we 5571 df-xp 5622 df-rel 5623 df-cnv 5624 df-co 5625 df-dm 5626 df-rn 5627 df-res 5628 df-ima 5629 df-pred 6248 df-ord 6309 df-on 6310 df-lim 6311 df-suc 6312 df-iota 6437 df-fun 6483 df-fn 6484 df-f 6485 df-f1 6486 df-fo 6487 df-f1o 6488 df-fv 6489 df-isom 6490 df-riota 7303 df-ov 7349 df-oprab 7350 df-mpo 7351 df-of 7610 df-ofr 7611 df-om 7797 df-1st 7921 df-2nd 7922 df-supp 8091 df-frecs 8211 df-wrecs 8242 df-recs 8291 df-rdg 8329 df-1o 8385 df-2o 8386 df-oadd 8389 df-omul 8390 df-er 8622 df-map 8752 df-pm 8753 df-ixp 8822 df-en 8870 df-dom 8871 df-sdom 8872 df-fin 8873 df-fsupp 9246 df-fi 9295 df-sup 9326 df-inf 9327 df-oi 9396 df-dju 9791 df-card 9829 df-acn 9832 df-pnf 11145 df-mnf 11146 df-xr 11147 df-ltxr 11148 df-le 11149 df-sub 11343 df-neg 11344 df-div 11772 df-nn 12123 df-2 12185 df-3 12186 df-4 12187 df-5 12188 df-6 12189 df-7 12190 df-8 12191 df-9 12192 df-n0 12379 df-z 12466 df-dec 12586 df-uz 12730 df-q 12844 df-rp 12888 df-xneg 13008 df-xadd 13009 df-xmul 13010 df-ioo 13246 df-ioc 13247 df-ico 13248 df-icc 13249 df-fz 13405 df-fzo 13552 df-fl 13693 df-mod 13771 df-seq 13906 df-exp 13966 df-fac 14178 df-bc 14207 df-hash 14235 df-shft 14971 df-cj 15003 df-re 15004 df-im 15005 df-sqrt 15139 df-abs 15140 df-limsup 15375 df-clim 15392 df-rlim 15393 df-sum 15591 df-ef 15971 df-sin 15973 df-cos 15974 df-pi 15976 df-struct 17055 df-sets 17072 df-slot 17090 df-ndx 17102 df-base 17118 df-ress 17139 df-plusg 17171 df-mulr 17172 df-starv 17173 df-sca 17174 df-vsca 17175 df-ip 17176 df-tset 17177 df-ple 17178 df-ds 17180 df-unif 17181 df-hom 17182 df-cco 17183 df-rest 17323 df-topn 17324 df-0g 17342 df-gsum 17343 df-topgen 17344 df-pt 17345 df-prds 17348 df-xrs 17403 df-qtop 17408 df-imas 17409 df-xps 17411 df-mre 17485 df-mrc 17486 df-acs 17488 df-mgm 18545 df-sgrp 18624 df-mnd 18640 df-submnd 18689 df-mulg 18978 df-cntz 19227 df-cmn 19692 df-psmet 21281 df-xmet 21282 df-met 21283 df-bl 21284 df-mopn 21285 df-fbas 21286 df-fg 21287 df-cnfld 21290 df-top 22807 df-topon 22824 df-topsp 22846 df-bases 22859 df-cld 22932 df-ntr 22933 df-cls 22934 df-nei 23011 df-lp 23049 df-perf 23050 df-cn 23140 df-cnp 23141 df-haus 23228 df-cmp 23300 df-tx 23475 df-hmeo 23668 df-fil 23759 df-fm 23851 df-flim 23852 df-flf 23853 df-xms 24233 df-ms 24234 df-tms 24235 df-cncf 24796 df-ovol 25390 df-vol 25391 df-mbf 25545 df-itg1 25546 df-itg2 25547 df-ibl 25548 df-itg 25549 df-0p 25596 df-limc 25792 df-dv 25793

This theorem is referenced by: wallispilem2 46103 wallispilem4 46105 wallispilem5 46106

W3C validator