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Mirrors > Home > MPE Home > Th. List > fta | Structured version Visualization version GIF version |
Description: The Fundamental Theorem of Algebra. Any polynomial with positive degree (i.e. non-constant) has a root. This is Metamath 100 proof #2. (Contributed by Mario Carneiro, 15-Sep-2014.) |
Ref | Expression |
---|---|
fta | ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) → ∃𝑧 ∈ ℂ (𝐹‘𝑧) = 0) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eqid 2778 | . . . 4 ⊢ (coeff‘𝐹) = (coeff‘𝐹) | |
2 | eqid 2778 | . . . 4 ⊢ (deg‘𝐹) = (deg‘𝐹) | |
3 | simpl 475 | . . . 4 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) → 𝐹 ∈ (Poly‘𝑆)) | |
4 | simpr 477 | . . . 4 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) → (deg‘𝐹) ∈ ℕ) | |
5 | eqid 2778 | . . . 4 ⊢ if(if(1 ≤ 𝑠, 𝑠, 1) ≤ ((abs‘(𝐹‘0)) / ((abs‘((coeff‘𝐹)‘(deg‘𝐹))) / 2)), ((abs‘(𝐹‘0)) / ((abs‘((coeff‘𝐹)‘(deg‘𝐹))) / 2)), if(1 ≤ 𝑠, 𝑠, 1)) = if(if(1 ≤ 𝑠, 𝑠, 1) ≤ ((abs‘(𝐹‘0)) / ((abs‘((coeff‘𝐹)‘(deg‘𝐹))) / 2)), ((abs‘(𝐹‘0)) / ((abs‘((coeff‘𝐹)‘(deg‘𝐹))) / 2)), if(1 ≤ 𝑠, 𝑠, 1)) | |
6 | eqid 2778 | . . . 4 ⊢ ((abs‘(𝐹‘0)) / ((abs‘((coeff‘𝐹)‘(deg‘𝐹))) / 2)) = ((abs‘(𝐹‘0)) / ((abs‘((coeff‘𝐹)‘(deg‘𝐹))) / 2)) | |
7 | 1, 2, 3, 4, 5, 6 | ftalem2 25353 | . . 3 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) → ∃𝑟 ∈ ℝ+ ∀𝑦 ∈ ℂ (𝑟 < (abs‘𝑦) → (abs‘(𝐹‘0)) < (abs‘(𝐹‘𝑦)))) |
8 | simpll 754 | . . . 4 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) ∧ (𝑟 ∈ ℝ+ ∧ ∀𝑦 ∈ ℂ (𝑟 < (abs‘𝑦) → (abs‘(𝐹‘0)) < (abs‘(𝐹‘𝑦))))) → 𝐹 ∈ (Poly‘𝑆)) | |
9 | simplr 756 | . . . 4 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) ∧ (𝑟 ∈ ℝ+ ∧ ∀𝑦 ∈ ℂ (𝑟 < (abs‘𝑦) → (abs‘(𝐹‘0)) < (abs‘(𝐹‘𝑦))))) → (deg‘𝐹) ∈ ℕ) | |
10 | eqid 2778 | . . . 4 ⊢ {𝑠 ∈ ℂ ∣ (abs‘𝑠) ≤ 𝑟} = {𝑠 ∈ ℂ ∣ (abs‘𝑠) ≤ 𝑟} | |
11 | eqid 2778 | . . . 4 ⊢ (TopOpen‘ℂfld) = (TopOpen‘ℂfld) | |
12 | simprl 758 | . . . 4 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) ∧ (𝑟 ∈ ℝ+ ∧ ∀𝑦 ∈ ℂ (𝑟 < (abs‘𝑦) → (abs‘(𝐹‘0)) < (abs‘(𝐹‘𝑦))))) → 𝑟 ∈ ℝ+) | |
13 | simprr 760 | . . . . 5 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) ∧ (𝑟 ∈ ℝ+ ∧ ∀𝑦 ∈ ℂ (𝑟 < (abs‘𝑦) → (abs‘(𝐹‘0)) < (abs‘(𝐹‘𝑦))))) → ∀𝑦 ∈ ℂ (𝑟 < (abs‘𝑦) → (abs‘(𝐹‘0)) < (abs‘(𝐹‘𝑦)))) | |
14 | fveq2 6499 | . . . . . . . 8 ⊢ (𝑦 = 𝑥 → (abs‘𝑦) = (abs‘𝑥)) | |
15 | 14 | breq2d 4941 | . . . . . . 7 ⊢ (𝑦 = 𝑥 → (𝑟 < (abs‘𝑦) ↔ 𝑟 < (abs‘𝑥))) |
16 | 2fveq3 6504 | . . . . . . . 8 ⊢ (𝑦 = 𝑥 → (abs‘(𝐹‘𝑦)) = (abs‘(𝐹‘𝑥))) | |
17 | 16 | breq2d 4941 | . . . . . . 7 ⊢ (𝑦 = 𝑥 → ((abs‘(𝐹‘0)) < (abs‘(𝐹‘𝑦)) ↔ (abs‘(𝐹‘0)) < (abs‘(𝐹‘𝑥)))) |
18 | 15, 17 | imbi12d 337 | . . . . . 6 ⊢ (𝑦 = 𝑥 → ((𝑟 < (abs‘𝑦) → (abs‘(𝐹‘0)) < (abs‘(𝐹‘𝑦))) ↔ (𝑟 < (abs‘𝑥) → (abs‘(𝐹‘0)) < (abs‘(𝐹‘𝑥))))) |
19 | 18 | cbvralv 3383 | . . . . 5 ⊢ (∀𝑦 ∈ ℂ (𝑟 < (abs‘𝑦) → (abs‘(𝐹‘0)) < (abs‘(𝐹‘𝑦))) ↔ ∀𝑥 ∈ ℂ (𝑟 < (abs‘𝑥) → (abs‘(𝐹‘0)) < (abs‘(𝐹‘𝑥)))) |
20 | 13, 19 | sylib 210 | . . . 4 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) ∧ (𝑟 ∈ ℝ+ ∧ ∀𝑦 ∈ ℂ (𝑟 < (abs‘𝑦) → (abs‘(𝐹‘0)) < (abs‘(𝐹‘𝑦))))) → ∀𝑥 ∈ ℂ (𝑟 < (abs‘𝑥) → (abs‘(𝐹‘0)) < (abs‘(𝐹‘𝑥)))) |
21 | 1, 2, 8, 9, 10, 11, 12, 20 | ftalem3 25354 | . . 3 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) ∧ (𝑟 ∈ ℝ+ ∧ ∀𝑦 ∈ ℂ (𝑟 < (abs‘𝑦) → (abs‘(𝐹‘0)) < (abs‘(𝐹‘𝑦))))) → ∃𝑧 ∈ ℂ ∀𝑥 ∈ ℂ (abs‘(𝐹‘𝑧)) ≤ (abs‘(𝐹‘𝑥))) |
22 | 7, 21 | rexlimddv 3236 | . 2 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) → ∃𝑧 ∈ ℂ ∀𝑥 ∈ ℂ (abs‘(𝐹‘𝑧)) ≤ (abs‘(𝐹‘𝑥))) |
23 | simpll 754 | . . . . . 6 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) ∧ (𝑧 ∈ ℂ ∧ (𝐹‘𝑧) ≠ 0)) → 𝐹 ∈ (Poly‘𝑆)) | |
24 | simplr 756 | . . . . . 6 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) ∧ (𝑧 ∈ ℂ ∧ (𝐹‘𝑧) ≠ 0)) → (deg‘𝐹) ∈ ℕ) | |
25 | simprl 758 | . . . . . 6 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) ∧ (𝑧 ∈ ℂ ∧ (𝐹‘𝑧) ≠ 0)) → 𝑧 ∈ ℂ) | |
26 | simprr 760 | . . . . . 6 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) ∧ (𝑧 ∈ ℂ ∧ (𝐹‘𝑧) ≠ 0)) → (𝐹‘𝑧) ≠ 0) | |
27 | 1, 2, 23, 24, 25, 26 | ftalem7 25358 | . . . . 5 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) ∧ (𝑧 ∈ ℂ ∧ (𝐹‘𝑧) ≠ 0)) → ¬ ∀𝑥 ∈ ℂ (abs‘(𝐹‘𝑧)) ≤ (abs‘(𝐹‘𝑥))) |
28 | 27 | expr 449 | . . . 4 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) ∧ 𝑧 ∈ ℂ) → ((𝐹‘𝑧) ≠ 0 → ¬ ∀𝑥 ∈ ℂ (abs‘(𝐹‘𝑧)) ≤ (abs‘(𝐹‘𝑥)))) |
29 | 28 | necon4ad 2986 | . . 3 ⊢ (((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) ∧ 𝑧 ∈ ℂ) → (∀𝑥 ∈ ℂ (abs‘(𝐹‘𝑧)) ≤ (abs‘(𝐹‘𝑥)) → (𝐹‘𝑧) = 0)) |
30 | 29 | reximdva 3219 | . 2 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) → (∃𝑧 ∈ ℂ ∀𝑥 ∈ ℂ (abs‘(𝐹‘𝑧)) ≤ (abs‘(𝐹‘𝑥)) → ∃𝑧 ∈ ℂ (𝐹‘𝑧) = 0)) |
31 | 22, 30 | mpd 15 | 1 ⊢ ((𝐹 ∈ (Poly‘𝑆) ∧ (deg‘𝐹) ∈ ℕ) → ∃𝑧 ∈ ℂ (𝐹‘𝑧) = 0) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 387 = wceq 1507 ∈ wcel 2050 ≠ wne 2967 ∀wral 3088 ∃wrex 3089 {crab 3092 ifcif 4350 class class class wbr 4929 ‘cfv 6188 (class class class)co 6976 ℂcc 10333 0cc0 10335 1c1 10336 < clt 10474 ≤ cle 10475 / cdiv 11098 ℕcn 11439 2c2 11495 ℝ+crp 12204 abscabs 14454 TopOpenctopn 16551 ℂfldccnfld 20247 Polycply 24477 coeffccoe 24479 degcdgr 24480 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1758 ax-4 1772 ax-5 1869 ax-6 1928 ax-7 1965 ax-8 2052 ax-9 2059 ax-10 2079 ax-11 2093 ax-12 2106 ax-13 2301 ax-ext 2750 ax-rep 5049 ax-sep 5060 ax-nul 5067 ax-pow 5119 ax-pr 5186 ax-un 7279 ax-inf2 8898 ax-cnex 10391 ax-resscn 10392 ax-1cn 10393 ax-icn 10394 ax-addcl 10395 ax-addrcl 10396 ax-mulcl 10397 ax-mulrcl 10398 ax-mulcom 10399 ax-addass 10400 ax-mulass 10401 ax-distr 10402 ax-i2m1 10403 ax-1ne0 10404 ax-1rid 10405 ax-rnegex 10406 ax-rrecex 10407 ax-cnre 10408 ax-pre-lttri 10409 ax-pre-lttrn 10410 ax-pre-ltadd 10411 ax-pre-mulgt0 10412 ax-pre-sup 10413 ax-addf 10414 ax-mulf 10415 |
This theorem depends on definitions: df-bi 199 df-an 388 df-or 834 df-3or 1069 df-3an 1070 df-tru 1510 df-fal 1520 df-ex 1743 df-nf 1747 df-sb 2016 df-mo 2547 df-eu 2584 df-clab 2759 df-cleq 2771 df-clel 2846 df-nfc 2918 df-ne 2968 df-nel 3074 df-ral 3093 df-rex 3094 df-reu 3095 df-rmo 3096 df-rab 3097 df-v 3417 df-sbc 3682 df-csb 3787 df-dif 3832 df-un 3834 df-in 3836 df-ss 3843 df-pss 3845 df-nul 4179 df-if 4351 df-pw 4424 df-sn 4442 df-pr 4444 df-tp 4446 df-op 4448 df-uni 4713 df-int 4750 df-iun 4794 df-iin 4795 df-br 4930 df-opab 4992 df-mpt 5009 df-tr 5031 df-id 5312 df-eprel 5317 df-po 5326 df-so 5327 df-fr 5366 df-se 5367 df-we 5368 df-xp 5413 df-rel 5414 df-cnv 5415 df-co 5416 df-dm 5417 df-rn 5418 df-res 5419 df-ima 5420 df-pred 5986 df-ord 6032 df-on 6033 df-lim 6034 df-suc 6035 df-iota 6152 df-fun 6190 df-fn 6191 df-f 6192 df-f1 6193 df-fo 6194 df-f1o 6195 df-fv 6196 df-isom 6197 df-riota 6937 df-ov 6979 df-oprab 6980 df-mpo 6981 df-of 7227 df-om 7397 df-1st 7501 df-2nd 7502 df-supp 7634 df-wrecs 7750 df-recs 7812 df-rdg 7850 df-1o 7905 df-2o 7906 df-oadd 7909 df-er 8089 df-map 8208 df-pm 8209 df-ixp 8260 df-en 8307 df-dom 8308 df-sdom 8309 df-fin 8310 df-fsupp 8629 df-fi 8670 df-sup 8701 df-inf 8702 df-oi 8769 df-card 9162 df-cda 9388 df-pnf 10476 df-mnf 10477 df-xr 10478 df-ltxr 10479 df-le 10480 df-sub 10672 df-neg 10673 df-div 11099 df-nn 11440 df-2 11503 df-3 11504 df-4 11505 df-5 11506 df-6 11507 df-7 11508 df-8 11509 df-9 11510 df-n0 11708 df-z 11794 df-dec 11912 df-uz 12059 df-q 12163 df-rp 12205 df-xneg 12324 df-xadd 12325 df-xmul 12326 df-ioo 12558 df-ioc 12559 df-ico 12560 df-icc 12561 df-fz 12709 df-fzo 12850 df-fl 12977 df-mod 13053 df-seq 13185 df-exp 13245 df-fac 13449 df-bc 13478 df-hash 13506 df-shft 14287 df-cj 14319 df-re 14320 df-im 14321 df-sqrt 14455 df-abs 14456 df-limsup 14689 df-clim 14706 df-rlim 14707 df-sum 14904 df-ef 15281 df-sin 15283 df-cos 15284 df-pi 15286 df-struct 16341 df-ndx 16342 df-slot 16343 df-base 16345 df-sets 16346 df-ress 16347 df-plusg 16434 df-mulr 16435 df-starv 16436 df-sca 16437 df-vsca 16438 df-ip 16439 df-tset 16440 df-ple 16441 df-ds 16443 df-unif 16444 df-hom 16445 df-cco 16446 df-rest 16552 df-topn 16553 df-0g 16571 df-gsum 16572 df-topgen 16573 df-pt 16574 df-prds 16577 df-xrs 16631 df-qtop 16636 df-imas 16637 df-xps 16639 df-mre 16715 df-mrc 16716 df-acs 16718 df-mgm 17710 df-sgrp 17752 df-mnd 17763 df-submnd 17804 df-mulg 18012 df-cntz 18218 df-cmn 18668 df-psmet 20239 df-xmet 20240 df-met 20241 df-bl 20242 df-mopn 20243 df-fbas 20244 df-fg 20245 df-cnfld 20248 df-top 21206 df-topon 21223 df-topsp 21245 df-bases 21258 df-cld 21331 df-ntr 21332 df-cls 21333 df-nei 21410 df-lp 21448 df-perf 21449 df-cn 21539 df-cnp 21540 df-haus 21627 df-cmp 21699 df-tx 21874 df-hmeo 22067 df-fil 22158 df-fm 22250 df-flim 22251 df-flf 22252 df-xms 22633 df-ms 22634 df-tms 22635 df-cncf 23189 df-0p 23974 df-limc 24167 df-dv 24168 df-ply 24481 df-idp 24482 df-coe 24483 df-dgr 24484 df-log 24841 df-cxp 24842 |
This theorem is referenced by: (None) |
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