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Mirrors > Home > MPE Home > Th. List > cosord | Structured version Visualization version GIF version |
Description: Cosine is decreasing over the closed interval from 0 to π. (Contributed by Paul Chapman, 16-Mar-2008.) (Proof shortened by Mario Carneiro, 10-May-2014.) |
Ref | Expression |
---|---|
cosord | ⊢ ((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) → (𝐴 < 𝐵 ↔ (cos‘𝐵) < (cos‘𝐴))) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simpll 755 | . . . 4 ⊢ (((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) ∧ 𝐴 < 𝐵) → 𝐴 ∈ (0[,]π)) | |
2 | simplr 757 | . . . 4 ⊢ (((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) ∧ 𝐴 < 𝐵) → 𝐵 ∈ (0[,]π)) | |
3 | simpr 477 | . . . 4 ⊢ (((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) ∧ 𝐴 < 𝐵) → 𝐴 < 𝐵) | |
4 | 1, 2, 3 | cosordlem 24831 | . . 3 ⊢ (((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) ∧ 𝐴 < 𝐵) → (cos‘𝐵) < (cos‘𝐴)) |
5 | 4 | ex 405 | . 2 ⊢ ((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) → (𝐴 < 𝐵 → (cos‘𝐵) < (cos‘𝐴))) |
6 | fveq2 6496 | . . . . . . 7 ⊢ (𝐴 = 𝐵 → (cos‘𝐴) = (cos‘𝐵)) | |
7 | 6 | eqcomd 2777 | . . . . . 6 ⊢ (𝐴 = 𝐵 → (cos‘𝐵) = (cos‘𝐴)) |
8 | 7 | a1i 11 | . . . . 5 ⊢ ((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) → (𝐴 = 𝐵 → (cos‘𝐵) = (cos‘𝐴))) |
9 | simplr 757 | . . . . . . 7 ⊢ (((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) ∧ 𝐵 < 𝐴) → 𝐵 ∈ (0[,]π)) | |
10 | simpll 755 | . . . . . . 7 ⊢ (((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) ∧ 𝐵 < 𝐴) → 𝐴 ∈ (0[,]π)) | |
11 | simpr 477 | . . . . . . 7 ⊢ (((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) ∧ 𝐵 < 𝐴) → 𝐵 < 𝐴) | |
12 | 9, 10, 11 | cosordlem 24831 | . . . . . 6 ⊢ (((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) ∧ 𝐵 < 𝐴) → (cos‘𝐴) < (cos‘𝐵)) |
13 | 12 | ex 405 | . . . . 5 ⊢ ((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) → (𝐵 < 𝐴 → (cos‘𝐴) < (cos‘𝐵))) |
14 | 8, 13 | orim12d 948 | . . . 4 ⊢ ((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) → ((𝐴 = 𝐵 ∨ 𝐵 < 𝐴) → ((cos‘𝐵) = (cos‘𝐴) ∨ (cos‘𝐴) < (cos‘𝐵)))) |
15 | 14 | con3d 150 | . . 3 ⊢ ((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) → (¬ ((cos‘𝐵) = (cos‘𝐴) ∨ (cos‘𝐴) < (cos‘𝐵)) → ¬ (𝐴 = 𝐵 ∨ 𝐵 < 𝐴))) |
16 | 0re 10439 | . . . . . 6 ⊢ 0 ∈ ℝ | |
17 | pire 24762 | . . . . . 6 ⊢ π ∈ ℝ | |
18 | 16, 17 | elicc2i 12616 | . . . . 5 ⊢ (𝐴 ∈ (0[,]π) ↔ (𝐴 ∈ ℝ ∧ 0 ≤ 𝐴 ∧ 𝐴 ≤ π)) |
19 | 18 | simp1bi 1126 | . . . 4 ⊢ (𝐴 ∈ (0[,]π) → 𝐴 ∈ ℝ) |
20 | 16, 17 | elicc2i 12616 | . . . . 5 ⊢ (𝐵 ∈ (0[,]π) ↔ (𝐵 ∈ ℝ ∧ 0 ≤ 𝐵 ∧ 𝐵 ≤ π)) |
21 | 20 | simp1bi 1126 | . . . 4 ⊢ (𝐵 ∈ (0[,]π) → 𝐵 ∈ ℝ) |
22 | recoscl 15352 | . . . . 5 ⊢ (𝐵 ∈ ℝ → (cos‘𝐵) ∈ ℝ) | |
23 | recoscl 15352 | . . . . 5 ⊢ (𝐴 ∈ ℝ → (cos‘𝐴) ∈ ℝ) | |
24 | axlttri 10510 | . . . . 5 ⊢ (((cos‘𝐵) ∈ ℝ ∧ (cos‘𝐴) ∈ ℝ) → ((cos‘𝐵) < (cos‘𝐴) ↔ ¬ ((cos‘𝐵) = (cos‘𝐴) ∨ (cos‘𝐴) < (cos‘𝐵)))) | |
25 | 22, 23, 24 | syl2anr 588 | . . . 4 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → ((cos‘𝐵) < (cos‘𝐴) ↔ ¬ ((cos‘𝐵) = (cos‘𝐴) ∨ (cos‘𝐴) < (cos‘𝐵)))) |
26 | 19, 21, 25 | syl2an 587 | . . 3 ⊢ ((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) → ((cos‘𝐵) < (cos‘𝐴) ↔ ¬ ((cos‘𝐵) = (cos‘𝐴) ∨ (cos‘𝐴) < (cos‘𝐵)))) |
27 | axlttri 10510 | . . . 4 ⊢ ((𝐴 ∈ ℝ ∧ 𝐵 ∈ ℝ) → (𝐴 < 𝐵 ↔ ¬ (𝐴 = 𝐵 ∨ 𝐵 < 𝐴))) | |
28 | 19, 21, 27 | syl2an 587 | . . 3 ⊢ ((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) → (𝐴 < 𝐵 ↔ ¬ (𝐴 = 𝐵 ∨ 𝐵 < 𝐴))) |
29 | 15, 26, 28 | 3imtr4d 286 | . 2 ⊢ ((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) → ((cos‘𝐵) < (cos‘𝐴) → 𝐴 < 𝐵)) |
30 | 5, 29 | impbid 204 | 1 ⊢ ((𝐴 ∈ (0[,]π) ∧ 𝐵 ∈ (0[,]π)) → (𝐴 < 𝐵 ↔ (cos‘𝐵) < (cos‘𝐴))) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ↔ wb 198 ∧ wa 387 ∨ wo 834 = wceq 1508 ∈ wcel 2051 class class class wbr 4925 ‘cfv 6185 (class class class)co 6974 ℝcr 10332 0cc0 10333 < clt 10472 ≤ cle 10473 [,]cicc 12555 cosccos 15276 πcpi 15278 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1759 ax-4 1773 ax-5 1870 ax-6 1929 ax-7 1966 ax-8 2053 ax-9 2060 ax-10 2080 ax-11 2094 ax-12 2107 ax-13 2302 ax-ext 2743 ax-rep 5045 ax-sep 5056 ax-nul 5063 ax-pow 5115 ax-pr 5182 ax-un 7277 ax-inf2 8896 ax-cnex 10389 ax-resscn 10390 ax-1cn 10391 ax-icn 10392 ax-addcl 10393 ax-addrcl 10394 ax-mulcl 10395 ax-mulrcl 10396 ax-mulcom 10397 ax-addass 10398 ax-mulass 10399 ax-distr 10400 ax-i2m1 10401 ax-1ne0 10402 ax-1rid 10403 ax-rnegex 10404 ax-rrecex 10405 ax-cnre 10406 ax-pre-lttri 10407 ax-pre-lttrn 10408 ax-pre-ltadd 10409 ax-pre-mulgt0 10410 ax-pre-sup 10411 ax-addf 10412 ax-mulf 10413 |
This theorem depends on definitions: df-bi 199 df-an 388 df-or 835 df-3or 1070 df-3an 1071 df-tru 1511 df-fal 1521 df-ex 1744 df-nf 1748 df-sb 2017 df-mo 2548 df-eu 2585 df-clab 2752 df-cleq 2764 df-clel 2839 df-nfc 2911 df-ne 2961 df-nel 3067 df-ral 3086 df-rex 3087 df-reu 3088 df-rmo 3089 df-rab 3090 df-v 3410 df-sbc 3675 df-csb 3780 df-dif 3825 df-un 3827 df-in 3829 df-ss 3836 df-pss 3838 df-nul 4173 df-if 4345 df-pw 4418 df-sn 4436 df-pr 4438 df-tp 4440 df-op 4442 df-uni 4709 df-int 4746 df-iun 4790 df-iin 4791 df-br 4926 df-opab 4988 df-mpt 5005 df-tr 5027 df-id 5308 df-eprel 5313 df-po 5322 df-so 5323 df-fr 5362 df-se 5363 df-we 5364 df-xp 5409 df-rel 5410 df-cnv 5411 df-co 5412 df-dm 5413 df-rn 5414 df-res 5415 df-ima 5416 df-pred 5983 df-ord 6029 df-on 6030 df-lim 6031 df-suc 6032 df-iota 6149 df-fun 6187 df-fn 6188 df-f 6189 df-f1 6190 df-fo 6191 df-f1o 6192 df-fv 6193 df-isom 6194 df-riota 6935 df-ov 6977 df-oprab 6978 df-mpo 6979 df-of 7225 df-om 7395 df-1st 7499 df-2nd 7500 df-supp 7632 df-wrecs 7748 df-recs 7810 df-rdg 7848 df-1o 7903 df-2o 7904 df-oadd 7907 df-er 8087 df-map 8206 df-pm 8207 df-ixp 8258 df-en 8305 df-dom 8306 df-sdom 8307 df-fin 8308 df-fsupp 8627 df-fi 8668 df-sup 8699 df-inf 8700 df-oi 8767 df-card 9160 df-cda 9386 df-pnf 10474 df-mnf 10475 df-xr 10476 df-ltxr 10477 df-le 10478 df-sub 10670 df-neg 10671 df-div 11097 df-nn 11438 df-2 11501 df-3 11502 df-4 11503 df-5 11504 df-6 11505 df-7 11506 df-8 11507 df-9 11508 df-n0 11706 df-z 11792 df-dec 11910 df-uz 12057 df-q 12161 df-rp 12203 df-xneg 12322 df-xadd 12323 df-xmul 12324 df-ioo 12556 df-ioc 12557 df-ico 12558 df-icc 12559 df-fz 12707 df-fzo 12848 df-fl 12975 df-seq 13183 df-exp 13243 df-fac 13447 df-bc 13476 df-hash 13504 df-shft 14285 df-cj 14317 df-re 14318 df-im 14319 df-sqrt 14453 df-abs 14454 df-limsup 14687 df-clim 14704 df-rlim 14705 df-sum 14902 df-ef 15279 df-sin 15281 df-cos 15282 df-pi 15284 df-struct 16339 df-ndx 16340 df-slot 16341 df-base 16343 df-sets 16344 df-ress 16345 df-plusg 16432 df-mulr 16433 df-starv 16434 df-sca 16435 df-vsca 16436 df-ip 16437 df-tset 16438 df-ple 16439 df-ds 16441 df-unif 16442 df-hom 16443 df-cco 16444 df-rest 16550 df-topn 16551 df-0g 16569 df-gsum 16570 df-topgen 16571 df-pt 16572 df-prds 16575 df-xrs 16629 df-qtop 16634 df-imas 16635 df-xps 16637 df-mre 16727 df-mrc 16728 df-acs 16730 df-mgm 17722 df-sgrp 17764 df-mnd 17775 df-submnd 17816 df-mulg 18024 df-cntz 18230 df-cmn 18680 df-psmet 20254 df-xmet 20255 df-met 20256 df-bl 20257 df-mopn 20258 df-fbas 20259 df-fg 20260 df-cnfld 20263 df-top 21221 df-topon 21238 df-topsp 21260 df-bases 21273 df-cld 21346 df-ntr 21347 df-cls 21348 df-nei 21425 df-lp 21463 df-perf 21464 df-cn 21554 df-cnp 21555 df-haus 21642 df-tx 21889 df-hmeo 22082 df-fil 22173 df-fm 22265 df-flim 22266 df-flf 22267 df-xms 22648 df-ms 22649 df-tms 22650 df-cncf 23204 df-limc 24182 df-dv 24183 |
This theorem is referenced by: cos11 24833 sinord 24834 tanord1 24837 argregt0 24909 argrege0 24910 |
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