onetansqsecsq - Mathbox for David A. Wheeler

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Theorem onetansqsecsq 47893

Description: Prove the tangent squared secant squared identity (1 + ((tan A ) ^ 2 ) ) = ( ( sec 𝐴)↑2)). (Contributed by David A. Wheeler, 25-May-2015.)

**Assertion**
Ref	Expression
onetansqsecsq	⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → (1 + ((tan‘𝐴)↑2)) = ((sec‘𝐴)↑2))

**Proof of Theorem onetansqsecsq**
Step	Hyp	Ref	Expression
1		coscl 16074	. . . . . . . . . 10 ⊢ (𝐴 ∈ ℂ → (cos‘𝐴) ∈ ℂ)
2		sqeq0 14089	. . . . . . . . . 10 ⊢ ((cos‘𝐴) ∈ ℂ → (((cos‘𝐴)↑2) = 0 ↔ (cos‘𝐴) = 0))
3	1, 2	syl 17	. . . . . . . . 9 ⊢ (𝐴 ∈ ℂ → (((cos‘𝐴)↑2) = 0 ↔ (cos‘𝐴) = 0))
4	3	necon3bid 2983	. . . . . . . 8 ⊢ (𝐴 ∈ ℂ → (((cos‘𝐴)↑2) ≠ 0 ↔ (cos‘𝐴) ≠ 0))
5	4	biimpar 476	. . . . . . 7 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → ((cos‘𝐴)↑2) ≠ 0)
6	1	sqcld 14113	. . . . . . . 8 ⊢ (𝐴 ∈ ℂ → ((cos‘𝐴)↑2) ∈ ℂ)
7		divid 11905	. . . . . . . 8 ⊢ ((((cos‘𝐴)↑2) ∈ ℂ ∧ ((cos‘𝐴)↑2) ≠ 0) → (((cos‘𝐴)↑2) / ((cos‘𝐴)↑2)) = 1)
8	6, 7	sylan 578	. . . . . . 7 ⊢ ((𝐴 ∈ ℂ ∧ ((cos‘𝐴)↑2) ≠ 0) → (((cos‘𝐴)↑2) / ((cos‘𝐴)↑2)) = 1)
9	5, 8	syldan 589	. . . . . 6 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → (((cos‘𝐴)↑2) / ((cos‘𝐴)↑2)) = 1)
10	9	eqcomd 2736	. . . . 5 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → 1 = (((cos‘𝐴)↑2) / ((cos‘𝐴)↑2)))
11		tanval 16075	. . . . . . 7 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → (tan‘𝐴) = ((sin‘𝐴) / (cos‘𝐴)))
12	11	oveq1d 7426	. . . . . 6 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → ((tan‘𝐴)↑2) = (((sin‘𝐴) / (cos‘𝐴))↑2))
13		2nn0 12493	. . . . . . . . . 10 ⊢ 2 ∈ ℕ₀
14		sincl 16073	. . . . . . . . . . 11 ⊢ (𝐴 ∈ ℂ → (sin‘𝐴) ∈ ℂ)
15		expdiv 14083	. . . . . . . . . . 11 ⊢ (((sin‘𝐴) ∈ ℂ ∧ ((cos‘𝐴) ∈ ℂ ∧ (cos‘𝐴) ≠ 0) ∧ 2 ∈ ℕ₀) → (((sin‘𝐴) / (cos‘𝐴))↑2) = (((sin‘𝐴)↑2) / ((cos‘𝐴)↑2)))
16	14, 15	syl3an1 1161	. . . . . . . . . 10 ⊢ ((𝐴 ∈ ℂ ∧ ((cos‘𝐴) ∈ ℂ ∧ (cos‘𝐴) ≠ 0) ∧ 2 ∈ ℕ₀) → (((sin‘𝐴) / (cos‘𝐴))↑2) = (((sin‘𝐴)↑2) / ((cos‘𝐴)↑2)))
17	13, 16	mp3an3 1448	. . . . . . . . 9 ⊢ ((𝐴 ∈ ℂ ∧ ((cos‘𝐴) ∈ ℂ ∧ (cos‘𝐴) ≠ 0)) → (((sin‘𝐴) / (cos‘𝐴))↑2) = (((sin‘𝐴)↑2) / ((cos‘𝐴)↑2)))
18	17	3impb 1113	. . . . . . . 8 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → (((sin‘𝐴) / (cos‘𝐴))↑2) = (((sin‘𝐴)↑2) / ((cos‘𝐴)↑2)))
19	1, 18	syl3an2 1162	. . . . . . 7 ⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → (((sin‘𝐴) / (cos‘𝐴))↑2) = (((sin‘𝐴)↑2) / ((cos‘𝐴)↑2)))
20	19	3anidm12 1417	. . . . . 6 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → (((sin‘𝐴) / (cos‘𝐴))↑2) = (((sin‘𝐴)↑2) / ((cos‘𝐴)↑2)))
21	12, 20	eqtrd 2770	. . . . 5 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → ((tan‘𝐴)↑2) = (((sin‘𝐴)↑2) / ((cos‘𝐴)↑2)))
22	10, 21	oveq12d 7429	. . . 4 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → (1 + ((tan‘𝐴)↑2)) = ((((cos‘𝐴)↑2) / ((cos‘𝐴)↑2)) + (((sin‘𝐴)↑2) / ((cos‘𝐴)↑2))))
23	14	sqcld 14113	. . . . . . . . . 10 ⊢ (𝐴 ∈ ℂ → ((sin‘𝐴)↑2) ∈ ℂ)
24		divdir 11901	. . . . . . . . . . 11 ⊢ ((((cos‘𝐴)↑2) ∈ ℂ ∧ ((sin‘𝐴)↑2) ∈ ℂ ∧ (((cos‘𝐴)↑2) ∈ ℂ ∧ ((cos‘𝐴)↑2) ≠ 0)) → ((((cos‘𝐴)↑2) + ((sin‘𝐴)↑2)) / ((cos‘𝐴)↑2)) = ((((cos‘𝐴)↑2) / ((cos‘𝐴)↑2)) + (((sin‘𝐴)↑2) / ((cos‘𝐴)↑2))))
25	6, 24	syl3an1 1161	. . . . . . . . . 10 ⊢ ((𝐴 ∈ ℂ ∧ ((sin‘𝐴)↑2) ∈ ℂ ∧ (((cos‘𝐴)↑2) ∈ ℂ ∧ ((cos‘𝐴)↑2) ≠ 0)) → ((((cos‘𝐴)↑2) + ((sin‘𝐴)↑2)) / ((cos‘𝐴)↑2)) = ((((cos‘𝐴)↑2) / ((cos‘𝐴)↑2)) + (((sin‘𝐴)↑2) / ((cos‘𝐴)↑2))))
26	23, 25	syl3an2 1162	. . . . . . . . 9 ⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ∈ ℂ ∧ (((cos‘𝐴)↑2) ∈ ℂ ∧ ((cos‘𝐴)↑2) ≠ 0)) → ((((cos‘𝐴)↑2) + ((sin‘𝐴)↑2)) / ((cos‘𝐴)↑2)) = ((((cos‘𝐴)↑2) / ((cos‘𝐴)↑2)) + (((sin‘𝐴)↑2) / ((cos‘𝐴)↑2))))
27	26	3anidm12 1417	. . . . . . . 8 ⊢ ((𝐴 ∈ ℂ ∧ (((cos‘𝐴)↑2) ∈ ℂ ∧ ((cos‘𝐴)↑2) ≠ 0)) → ((((cos‘𝐴)↑2) + ((sin‘𝐴)↑2)) / ((cos‘𝐴)↑2)) = ((((cos‘𝐴)↑2) / ((cos‘𝐴)↑2)) + (((sin‘𝐴)↑2) / ((cos‘𝐴)↑2))))
28	27	3impb 1113	. . . . . . 7 ⊢ ((𝐴 ∈ ℂ ∧ ((cos‘𝐴)↑2) ∈ ℂ ∧ ((cos‘𝐴)↑2) ≠ 0) → ((((cos‘𝐴)↑2) + ((sin‘𝐴)↑2)) / ((cos‘𝐴)↑2)) = ((((cos‘𝐴)↑2) / ((cos‘𝐴)↑2)) + (((sin‘𝐴)↑2) / ((cos‘𝐴)↑2))))
29	6, 28	syl3an2 1162	. . . . . 6 ⊢ ((𝐴 ∈ ℂ ∧ 𝐴 ∈ ℂ ∧ ((cos‘𝐴)↑2) ≠ 0) → ((((cos‘𝐴)↑2) + ((sin‘𝐴)↑2)) / ((cos‘𝐴)↑2)) = ((((cos‘𝐴)↑2) / ((cos‘𝐴)↑2)) + (((sin‘𝐴)↑2) / ((cos‘𝐴)↑2))))
30	29	3anidm12 1417	. . . . 5 ⊢ ((𝐴 ∈ ℂ ∧ ((cos‘𝐴)↑2) ≠ 0) → ((((cos‘𝐴)↑2) + ((sin‘𝐴)↑2)) / ((cos‘𝐴)↑2)) = ((((cos‘𝐴)↑2) / ((cos‘𝐴)↑2)) + (((sin‘𝐴)↑2) / ((cos‘𝐴)↑2))))
31	5, 30	syldan 589	. . . 4 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → ((((cos‘𝐴)↑2) + ((sin‘𝐴)↑2)) / ((cos‘𝐴)↑2)) = ((((cos‘𝐴)↑2) / ((cos‘𝐴)↑2)) + (((sin‘𝐴)↑2) / ((cos‘𝐴)↑2))))
32	22, 31	eqtr4d 2773	. . 3 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → (1 + ((tan‘𝐴)↑2)) = ((((cos‘𝐴)↑2) + ((sin‘𝐴)↑2)) / ((cos‘𝐴)↑2)))
33	23, 6	addcomd 11420	. . . . . 6 ⊢ (𝐴 ∈ ℂ → (((sin‘𝐴)↑2) + ((cos‘𝐴)↑2)) = (((cos‘𝐴)↑2) + ((sin‘𝐴)↑2)))
34		sincossq 16123	. . . . . 6 ⊢ (𝐴 ∈ ℂ → (((sin‘𝐴)↑2) + ((cos‘𝐴)↑2)) = 1)
35	33, 34	eqtr3d 2772	. . . . 5 ⊢ (𝐴 ∈ ℂ → (((cos‘𝐴)↑2) + ((sin‘𝐴)↑2)) = 1)
36	35	oveq1d 7426	. . . 4 ⊢ (𝐴 ∈ ℂ → ((((cos‘𝐴)↑2) + ((sin‘𝐴)↑2)) / ((cos‘𝐴)↑2)) = (1 / ((cos‘𝐴)↑2)))
37	36	adantr 479	. . 3 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → ((((cos‘𝐴)↑2) + ((sin‘𝐴)↑2)) / ((cos‘𝐴)↑2)) = (1 / ((cos‘𝐴)↑2)))
38	32, 37	eqtrd 2770	. 2 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → (1 + ((tan‘𝐴)↑2)) = (1 / ((cos‘𝐴)↑2)))
39		secval 47879	. . . 4 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → (sec‘𝐴) = (1 / (cos‘𝐴)))
40	39	oveq1d 7426	. . 3 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → ((sec‘𝐴)↑2) = ((1 / (cos‘𝐴))↑2))
41		ax-1cn 11170	. . . . . 6 ⊢ 1 ∈ ℂ
42		expdiv 14083	. . . . . 6 ⊢ ((1 ∈ ℂ ∧ ((cos‘𝐴) ∈ ℂ ∧ (cos‘𝐴) ≠ 0) ∧ 2 ∈ ℕ₀) → ((1 / (cos‘𝐴))↑2) = ((1↑2) / ((cos‘𝐴)↑2)))
43	41, 13, 42	mp3an13 1450	. . . . 5 ⊢ (((cos‘𝐴) ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → ((1 / (cos‘𝐴))↑2) = ((1↑2) / ((cos‘𝐴)↑2)))
44	1, 43	sylan 578	. . . 4 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → ((1 / (cos‘𝐴))↑2) = ((1↑2) / ((cos‘𝐴)↑2)))
45		sq1 14163	. . . . 5 ⊢ (1↑2) = 1
46	45	oveq1i 7421	. . . 4 ⊢ ((1↑2) / ((cos‘𝐴)↑2)) = (1 / ((cos‘𝐴)↑2))
47	44, 46	eqtrdi 2786	. . 3 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → ((1 / (cos‘𝐴))↑2) = (1 / ((cos‘𝐴)↑2)))
48	40, 47	eqtrd 2770	. 2 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → ((sec‘𝐴)↑2) = (1 / ((cos‘𝐴)↑2)))
49	38, 48	eqtr4d 2773	1 ⊢ ((𝐴 ∈ ℂ ∧ (cos‘𝐴) ≠ 0) → (1 + ((tan‘𝐴)↑2)) = ((sec‘𝐴)↑2))

Colors of variables: wff setvar class

Syntax hints: → wi 4 ↔ wb 205 ∧ wa 394 = wceq 1539 ∈ wcel 2104 ≠ wne 2938 ‘cfv 6542 (class class class)co 7411 ℂcc 11110 0cc0 11112 1c1 11113 + caddc 11115 / cdiv 11875 2c2 12271 ℕ₀cn0 12476 ↑cexp 14031 sincsin 16011 cosccos 16012 tanctan 16013 seccsec 47873

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1795 ax-4 1809 ax-5 1911 ax-6 1969 ax-7 2009 ax-8 2106 ax-9 2114 ax-10 2135 ax-11 2152 ax-12 2169 ax-ext 2701 ax-rep 5284 ax-sep 5298 ax-nul 5305 ax-pow 5362 ax-pr 5426 ax-un 7727 ax-inf2 9638 ax-cnex 11168 ax-resscn 11169 ax-1cn 11170 ax-icn 11171 ax-addcl 11172 ax-addrcl 11173 ax-mulcl 11174 ax-mulrcl 11175 ax-mulcom 11176 ax-addass 11177 ax-mulass 11178 ax-distr 11179 ax-i2m1 11180 ax-1ne0 11181 ax-1rid 11182 ax-rnegex 11183 ax-rrecex 11184 ax-cnre 11185 ax-pre-lttri 11186 ax-pre-lttrn 11187 ax-pre-ltadd 11188 ax-pre-mulgt0 11189 ax-pre-sup 11190

This theorem depends on definitions: df-bi 206 df-an 395 df-or 844 df-3or 1086 df-3an 1087 df-tru 1542 df-fal 1552 df-ex 1780 df-nf 1784 df-sb 2066 df-mo 2532 df-eu 2561 df-clab 2708 df-cleq 2722 df-clel 2808 df-nfc 2883 df-ne 2939 df-nel 3045 df-ral 3060 df-rex 3069 df-rmo 3374 df-reu 3375 df-rab 3431 df-v 3474 df-sbc 3777 df-csb 3893 df-dif 3950 df-un 3952 df-in 3954 df-ss 3964 df-pss 3966 df-nul 4322 df-if 4528 df-pw 4603 df-sn 4628 df-pr 4630 df-op 4634 df-uni 4908 df-int 4950 df-iun 4998 df-br 5148 df-opab 5210 df-mpt 5231 df-tr 5265 df-id 5573 df-eprel 5579 df-po 5587 df-so 5588 df-fr 5630 df-se 5631 df-we 5632 df-xp 5681 df-rel 5682 df-cnv 5683 df-co 5684 df-dm 5685 df-rn 5686 df-res 5687 df-ima 5688 df-pred 6299 df-ord 6366 df-on 6367 df-lim 6368 df-suc 6369 df-iota 6494 df-fun 6544 df-fn 6545 df-f 6546 df-f1 6547 df-fo 6548 df-f1o 6549 df-fv 6550 df-isom 6551 df-riota 7367 df-ov 7414 df-oprab 7415 df-mpo 7416 df-om 7858 df-1st 7977 df-2nd 7978 df-frecs 8268 df-wrecs 8299 df-recs 8373 df-rdg 8412 df-1o 8468 df-er 8705 df-pm 8825 df-en 8942 df-dom 8943 df-sdom 8944 df-fin 8945 df-sup 9439 df-inf 9440 df-oi 9507 df-card 9936 df-pnf 11254 df-mnf 11255 df-xr 11256 df-ltxr 11257 df-le 11258 df-sub 11450 df-neg 11451 df-div 11876 df-nn 12217 df-2 12279 df-3 12280 df-n0 12477 df-z 12563 df-uz 12827 df-rp 12979 df-ico 13334 df-fz 13489 df-fzo 13632 df-fl 13761 df-seq 13971 df-exp 14032 df-fac 14238 df-bc 14267 df-hash 14295 df-shft 15018 df-cj 15050 df-re 15051 df-im 15052 df-sqrt 15186 df-abs 15187 df-limsup 15419 df-clim 15436 df-rlim 15437 df-sum 15637 df-ef 16015 df-sin 16017 df-cos 16018 df-tan 16019 df-sec 47876

This theorem is referenced by: (None)

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