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Mirrors > Home > MPE Home > Th. List > recosf1o | Structured version Visualization version GIF version |
Description: The cosine function is a bijection when restricted to its principal domain. (Contributed by Mario Carneiro, 12-May-2014.) |
Ref | Expression |
---|---|
recosf1o | ⊢ (cos ↾ (0[,]π)):(0[,]π)–1-1-onto→(-1[,]1) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | cosf 16157 | . . . . . 6 ⊢ cos:ℂ⟶ℂ | |
2 | ffn 6736 | . . . . . 6 ⊢ (cos:ℂ⟶ℂ → cos Fn ℂ) | |
3 | 1, 2 | ax-mp 5 | . . . . 5 ⊢ cos Fn ℂ |
4 | 0re 11260 | . . . . . . 7 ⊢ 0 ∈ ℝ | |
5 | pire 26514 | . . . . . . 7 ⊢ π ∈ ℝ | |
6 | iccssre 13465 | . . . . . . 7 ⊢ ((0 ∈ ℝ ∧ π ∈ ℝ) → (0[,]π) ⊆ ℝ) | |
7 | 4, 5, 6 | mp2an 692 | . . . . . 6 ⊢ (0[,]π) ⊆ ℝ |
8 | ax-resscn 11209 | . . . . . 6 ⊢ ℝ ⊆ ℂ | |
9 | 7, 8 | sstri 4004 | . . . . 5 ⊢ (0[,]π) ⊆ ℂ |
10 | fnssres 6691 | . . . . 5 ⊢ ((cos Fn ℂ ∧ (0[,]π) ⊆ ℂ) → (cos ↾ (0[,]π)) Fn (0[,]π)) | |
11 | 3, 9, 10 | mp2an 692 | . . . 4 ⊢ (cos ↾ (0[,]π)) Fn (0[,]π) |
12 | fvres 6925 | . . . . . 6 ⊢ (𝑥 ∈ (0[,]π) → ((cos ↾ (0[,]π))‘𝑥) = (cos‘𝑥)) | |
13 | 7 | sseli 3990 | . . . . . . 7 ⊢ (𝑥 ∈ (0[,]π) → 𝑥 ∈ ℝ) |
14 | cosbnd2 16215 | . . . . . . 7 ⊢ (𝑥 ∈ ℝ → (cos‘𝑥) ∈ (-1[,]1)) | |
15 | 13, 14 | syl 17 | . . . . . 6 ⊢ (𝑥 ∈ (0[,]π) → (cos‘𝑥) ∈ (-1[,]1)) |
16 | 12, 15 | eqeltrd 2838 | . . . . 5 ⊢ (𝑥 ∈ (0[,]π) → ((cos ↾ (0[,]π))‘𝑥) ∈ (-1[,]1)) |
17 | 16 | rgen 3060 | . . . 4 ⊢ ∀𝑥 ∈ (0[,]π)((cos ↾ (0[,]π))‘𝑥) ∈ (-1[,]1) |
18 | ffnfv 7138 | . . . 4 ⊢ ((cos ↾ (0[,]π)):(0[,]π)⟶(-1[,]1) ↔ ((cos ↾ (0[,]π)) Fn (0[,]π) ∧ ∀𝑥 ∈ (0[,]π)((cos ↾ (0[,]π))‘𝑥) ∈ (-1[,]1))) | |
19 | 11, 17, 18 | mpbir2an 711 | . . 3 ⊢ (cos ↾ (0[,]π)):(0[,]π)⟶(-1[,]1) |
20 | fvres 6925 | . . . . . 6 ⊢ (𝑦 ∈ (0[,]π) → ((cos ↾ (0[,]π))‘𝑦) = (cos‘𝑦)) | |
21 | 12, 20 | eqeqan12d 2748 | . . . . 5 ⊢ ((𝑥 ∈ (0[,]π) ∧ 𝑦 ∈ (0[,]π)) → (((cos ↾ (0[,]π))‘𝑥) = ((cos ↾ (0[,]π))‘𝑦) ↔ (cos‘𝑥) = (cos‘𝑦))) |
22 | cos11 26589 | . . . . . 6 ⊢ ((𝑥 ∈ (0[,]π) ∧ 𝑦 ∈ (0[,]π)) → (𝑥 = 𝑦 ↔ (cos‘𝑥) = (cos‘𝑦))) | |
23 | 22 | biimprd 248 | . . . . 5 ⊢ ((𝑥 ∈ (0[,]π) ∧ 𝑦 ∈ (0[,]π)) → ((cos‘𝑥) = (cos‘𝑦) → 𝑥 = 𝑦)) |
24 | 21, 23 | sylbid 240 | . . . 4 ⊢ ((𝑥 ∈ (0[,]π) ∧ 𝑦 ∈ (0[,]π)) → (((cos ↾ (0[,]π))‘𝑥) = ((cos ↾ (0[,]π))‘𝑦) → 𝑥 = 𝑦)) |
25 | 24 | rgen2 3196 | . . 3 ⊢ ∀𝑥 ∈ (0[,]π)∀𝑦 ∈ (0[,]π)(((cos ↾ (0[,]π))‘𝑥) = ((cos ↾ (0[,]π))‘𝑦) → 𝑥 = 𝑦) |
26 | dff13 7274 | . . 3 ⊢ ((cos ↾ (0[,]π)):(0[,]π)–1-1→(-1[,]1) ↔ ((cos ↾ (0[,]π)):(0[,]π)⟶(-1[,]1) ∧ ∀𝑥 ∈ (0[,]π)∀𝑦 ∈ (0[,]π)(((cos ↾ (0[,]π))‘𝑥) = ((cos ↾ (0[,]π))‘𝑦) → 𝑥 = 𝑦))) | |
27 | 19, 25, 26 | mpbir2an 711 | . 2 ⊢ (cos ↾ (0[,]π)):(0[,]π)–1-1→(-1[,]1) |
28 | 4 | a1i 11 | . . . . . 6 ⊢ (𝑥 ∈ (-1[,]1) → 0 ∈ ℝ) |
29 | 5 | a1i 11 | . . . . . 6 ⊢ (𝑥 ∈ (-1[,]1) → π ∈ ℝ) |
30 | neg1rr 12378 | . . . . . . . 8 ⊢ -1 ∈ ℝ | |
31 | 1re 11258 | . . . . . . . 8 ⊢ 1 ∈ ℝ | |
32 | 30, 31 | elicc2i 13449 | . . . . . . 7 ⊢ (𝑥 ∈ (-1[,]1) ↔ (𝑥 ∈ ℝ ∧ -1 ≤ 𝑥 ∧ 𝑥 ≤ 1)) |
33 | 32 | simp1bi 1144 | . . . . . 6 ⊢ (𝑥 ∈ (-1[,]1) → 𝑥 ∈ ℝ) |
34 | pipos 26516 | . . . . . . 7 ⊢ 0 < π | |
35 | 34 | a1i 11 | . . . . . 6 ⊢ (𝑥 ∈ (-1[,]1) → 0 < π) |
36 | 9 | a1i 11 | . . . . . 6 ⊢ (𝑥 ∈ (-1[,]1) → (0[,]π) ⊆ ℂ) |
37 | coscn 26503 | . . . . . . 7 ⊢ cos ∈ (ℂ–cn→ℂ) | |
38 | 37 | a1i 11 | . . . . . 6 ⊢ (𝑥 ∈ (-1[,]1) → cos ∈ (ℂ–cn→ℂ)) |
39 | 7 | sseli 3990 | . . . . . . . 8 ⊢ (𝑧 ∈ (0[,]π) → 𝑧 ∈ ℝ) |
40 | 39 | recoscld 16176 | . . . . . . 7 ⊢ (𝑧 ∈ (0[,]π) → (cos‘𝑧) ∈ ℝ) |
41 | 40 | adantl 481 | . . . . . 6 ⊢ ((𝑥 ∈ (-1[,]1) ∧ 𝑧 ∈ (0[,]π)) → (cos‘𝑧) ∈ ℝ) |
42 | cospi 26528 | . . . . . . . 8 ⊢ (cos‘π) = -1 | |
43 | 32 | simp2bi 1145 | . . . . . . . 8 ⊢ (𝑥 ∈ (-1[,]1) → -1 ≤ 𝑥) |
44 | 42, 43 | eqbrtrid 5182 | . . . . . . 7 ⊢ (𝑥 ∈ (-1[,]1) → (cos‘π) ≤ 𝑥) |
45 | 32 | simp3bi 1146 | . . . . . . . 8 ⊢ (𝑥 ∈ (-1[,]1) → 𝑥 ≤ 1) |
46 | cos0 16182 | . . . . . . . 8 ⊢ (cos‘0) = 1 | |
47 | 45, 46 | breqtrrdi 5189 | . . . . . . 7 ⊢ (𝑥 ∈ (-1[,]1) → 𝑥 ≤ (cos‘0)) |
48 | 44, 47 | jca 511 | . . . . . 6 ⊢ (𝑥 ∈ (-1[,]1) → ((cos‘π) ≤ 𝑥 ∧ 𝑥 ≤ (cos‘0))) |
49 | 28, 29, 33, 35, 36, 38, 41, 48 | ivthle2 25505 | . . . . 5 ⊢ (𝑥 ∈ (-1[,]1) → ∃𝑦 ∈ (0[,]π)(cos‘𝑦) = 𝑥) |
50 | eqcom 2741 | . . . . . . 7 ⊢ (𝑥 = ((cos ↾ (0[,]π))‘𝑦) ↔ ((cos ↾ (0[,]π))‘𝑦) = 𝑥) | |
51 | 20 | eqeq1d 2736 | . . . . . . 7 ⊢ (𝑦 ∈ (0[,]π) → (((cos ↾ (0[,]π))‘𝑦) = 𝑥 ↔ (cos‘𝑦) = 𝑥)) |
52 | 50, 51 | bitrid 283 | . . . . . 6 ⊢ (𝑦 ∈ (0[,]π) → (𝑥 = ((cos ↾ (0[,]π))‘𝑦) ↔ (cos‘𝑦) = 𝑥)) |
53 | 52 | rexbiia 3089 | . . . . 5 ⊢ (∃𝑦 ∈ (0[,]π)𝑥 = ((cos ↾ (0[,]π))‘𝑦) ↔ ∃𝑦 ∈ (0[,]π)(cos‘𝑦) = 𝑥) |
54 | 49, 53 | sylibr 234 | . . . 4 ⊢ (𝑥 ∈ (-1[,]1) → ∃𝑦 ∈ (0[,]π)𝑥 = ((cos ↾ (0[,]π))‘𝑦)) |
55 | 54 | rgen 3060 | . . 3 ⊢ ∀𝑥 ∈ (-1[,]1)∃𝑦 ∈ (0[,]π)𝑥 = ((cos ↾ (0[,]π))‘𝑦) |
56 | dffo3 7121 | . . 3 ⊢ ((cos ↾ (0[,]π)):(0[,]π)–onto→(-1[,]1) ↔ ((cos ↾ (0[,]π)):(0[,]π)⟶(-1[,]1) ∧ ∀𝑥 ∈ (-1[,]1)∃𝑦 ∈ (0[,]π)𝑥 = ((cos ↾ (0[,]π))‘𝑦))) | |
57 | 19, 55, 56 | mpbir2an 711 | . 2 ⊢ (cos ↾ (0[,]π)):(0[,]π)–onto→(-1[,]1) |
58 | df-f1o 6569 | . 2 ⊢ ((cos ↾ (0[,]π)):(0[,]π)–1-1-onto→(-1[,]1) ↔ ((cos ↾ (0[,]π)):(0[,]π)–1-1→(-1[,]1) ∧ (cos ↾ (0[,]π)):(0[,]π)–onto→(-1[,]1))) | |
59 | 27, 57, 58 | mpbir2an 711 | 1 ⊢ (cos ↾ (0[,]π)):(0[,]π)–1-1-onto→(-1[,]1) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 395 = wceq 1536 ∈ wcel 2105 ∀wral 3058 ∃wrex 3067 ⊆ wss 3962 class class class wbr 5147 ↾ cres 5690 Fn wfn 6557 ⟶wf 6558 –1-1→wf1 6559 –onto→wfo 6560 –1-1-onto→wf1o 6561 ‘cfv 6562 (class class class)co 7430 ℂcc 11150 ℝcr 11151 0cc0 11152 1c1 11153 < clt 11292 ≤ cle 11293 -cneg 11490 [,]cicc 13386 cosccos 16096 πcpi 16098 –cn→ccncf 24915 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1791 ax-4 1805 ax-5 1907 ax-6 1964 ax-7 2004 ax-8 2107 ax-9 2115 ax-10 2138 ax-11 2154 ax-12 2174 ax-ext 2705 ax-rep 5284 ax-sep 5301 ax-nul 5311 ax-pow 5370 ax-pr 5437 ax-un 7753 ax-inf2 9678 ax-cnex 11208 ax-resscn 11209 ax-1cn 11210 ax-icn 11211 ax-addcl 11212 ax-addrcl 11213 ax-mulcl 11214 ax-mulrcl 11215 ax-mulcom 11216 ax-addass 11217 ax-mulass 11218 ax-distr 11219 ax-i2m1 11220 ax-1ne0 11221 ax-1rid 11222 ax-rnegex 11223 ax-rrecex 11224 ax-cnre 11225 ax-pre-lttri 11226 ax-pre-lttrn 11227 ax-pre-ltadd 11228 ax-pre-mulgt0 11229 ax-pre-sup 11230 ax-addf 11231 |
This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3or 1087 df-3an 1088 df-tru 1539 df-fal 1549 df-ex 1776 df-nf 1780 df-sb 2062 df-mo 2537 df-eu 2566 df-clab 2712 df-cleq 2726 df-clel 2813 df-nfc 2889 df-ne 2938 df-nel 3044 df-ral 3059 df-rex 3068 df-rmo 3377 df-reu 3378 df-rab 3433 df-v 3479 df-sbc 3791 df-csb 3908 df-dif 3965 df-un 3967 df-in 3969 df-ss 3979 df-pss 3982 df-nul 4339 df-if 4531 df-pw 4606 df-sn 4631 df-pr 4633 df-tp 4635 df-op 4637 df-uni 4912 df-int 4951 df-iun 4997 df-iin 4998 df-br 5148 df-opab 5210 df-mpt 5231 df-tr 5265 df-id 5582 df-eprel 5588 df-po 5596 df-so 5597 df-fr 5640 df-se 5641 df-we 5642 df-xp 5694 df-rel 5695 df-cnv 5696 df-co 5697 df-dm 5698 df-rn 5699 df-res 5700 df-ima 5701 df-pred 6322 df-ord 6388 df-on 6389 df-lim 6390 df-suc 6391 df-iota 6515 df-fun 6564 df-fn 6565 df-f 6566 df-f1 6567 df-fo 6568 df-f1o 6569 df-fv 6570 df-isom 6571 df-riota 7387 df-ov 7433 df-oprab 7434 df-mpo 7435 df-of 7696 df-om 7887 df-1st 8012 df-2nd 8013 df-supp 8184 df-frecs 8304 df-wrecs 8335 df-recs 8409 df-rdg 8448 df-1o 8504 df-2o 8505 df-er 8743 df-map 8866 df-pm 8867 df-ixp 8936 df-en 8984 df-dom 8985 df-sdom 8986 df-fin 8987 df-fsupp 9399 df-fi 9448 df-sup 9479 df-inf 9480 df-oi 9547 df-card 9976 df-pnf 11294 df-mnf 11295 df-xr 11296 df-ltxr 11297 df-le 11298 df-sub 11491 df-neg 11492 df-div 11918 df-nn 12264 df-2 12326 df-3 12327 df-4 12328 df-5 12329 df-6 12330 df-7 12331 df-8 12332 df-9 12333 df-n0 12524 df-z 12611 df-dec 12731 df-uz 12876 df-q 12988 df-rp 13032 df-xneg 13151 df-xadd 13152 df-xmul 13153 df-ioo 13387 df-ioc 13388 df-ico 13389 df-icc 13390 df-fz 13544 df-fzo 13691 df-fl 13828 df-seq 14039 df-exp 14099 df-fac 14309 df-bc 14338 df-hash 14366 df-shft 15102 df-cj 15134 df-re 15135 df-im 15136 df-sqrt 15270 df-abs 15271 df-limsup 15503 df-clim 15520 df-rlim 15521 df-sum 15719 df-ef 16099 df-sin 16101 df-cos 16102 df-pi 16104 df-struct 17180 df-sets 17197 df-slot 17215 df-ndx 17227 df-base 17245 df-ress 17274 df-plusg 17310 df-mulr 17311 df-starv 17312 df-sca 17313 df-vsca 17314 df-ip 17315 df-tset 17316 df-ple 17317 df-ds 17319 df-unif 17320 df-hom 17321 df-cco 17322 df-rest 17468 df-topn 17469 df-0g 17487 df-gsum 17488 df-topgen 17489 df-pt 17490 df-prds 17493 df-xrs 17548 df-qtop 17553 df-imas 17554 df-xps 17556 df-mre 17630 df-mrc 17631 df-acs 17633 df-mgm 18665 df-sgrp 18744 df-mnd 18760 df-submnd 18809 df-mulg 19098 df-cntz 19347 df-cmn 19814 df-psmet 21373 df-xmet 21374 df-met 21375 df-bl 21376 df-mopn 21377 df-fbas 21378 df-fg 21379 df-cnfld 21382 df-top 22915 df-topon 22932 df-topsp 22954 df-bases 22968 df-cld 23042 df-ntr 23043 df-cls 23044 df-nei 23121 df-lp 23159 df-perf 23160 df-cn 23250 df-cnp 23251 df-haus 23338 df-tx 23585 df-hmeo 23778 df-fil 23869 df-fm 23961 df-flim 23962 df-flf 23963 df-xms 24345 df-ms 24346 df-tms 24347 df-cncf 24917 df-limc 25915 df-dv 25916 |
This theorem is referenced by: resinf1o 26592 |
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