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Mirrors > Home > MPE Home > Th. List > chordthmlem | Structured version Visualization version GIF version |
Description: If M is the midpoint of AB and AQ = BQ, then QMB is a right angle. The proof uses ssscongptld 25408 to observe that, since AMQ and BMQ have equal sides, the angles QMB and QMA must be equal. Since they are supplementary, both must be right. (Contributed by David Moews, 28-Feb-2017.) |
Ref | Expression |
---|---|
chordthmlem.angdef | ⊢ 𝐹 = (𝑥 ∈ (ℂ ∖ {0}), 𝑦 ∈ (ℂ ∖ {0}) ↦ (ℑ‘(log‘(𝑦 / 𝑥)))) |
chordthmlem.A | ⊢ (𝜑 → 𝐴 ∈ ℂ) |
chordthmlem.B | ⊢ (𝜑 → 𝐵 ∈ ℂ) |
chordthmlem.Q | ⊢ (𝜑 → 𝑄 ∈ ℂ) |
chordthmlem.M | ⊢ (𝜑 → 𝑀 = ((𝐴 + 𝐵) / 2)) |
chordthmlem.ABequidistQ | ⊢ (𝜑 → (abs‘(𝐴 − 𝑄)) = (abs‘(𝐵 − 𝑄))) |
chordthmlem.AneB | ⊢ (𝜑 → 𝐴 ≠ 𝐵) |
chordthmlem.QneM | ⊢ (𝜑 → 𝑄 ≠ 𝑀) |
Ref | Expression |
---|---|
chordthmlem | ⊢ (𝜑 → ((𝑄 − 𝑀)𝐹(𝐵 − 𝑀)) ∈ {(π / 2), -(π / 2)}) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | negpitopissre 25132 | . . . . . 6 ⊢ (-π(,]π) ⊆ ℝ | |
2 | chordthmlem.angdef | . . . . . . 7 ⊢ 𝐹 = (𝑥 ∈ (ℂ ∖ {0}), 𝑦 ∈ (ℂ ∖ {0}) ↦ (ℑ‘(log‘(𝑦 / 𝑥)))) | |
3 | chordthmlem.Q | . . . . . . . 8 ⊢ (𝜑 → 𝑄 ∈ ℂ) | |
4 | chordthmlem.M | . . . . . . . . 9 ⊢ (𝜑 → 𝑀 = ((𝐴 + 𝐵) / 2)) | |
5 | chordthmlem.A | . . . . . . . . . . 11 ⊢ (𝜑 → 𝐴 ∈ ℂ) | |
6 | chordthmlem.B | . . . . . . . . . . 11 ⊢ (𝜑 → 𝐵 ∈ ℂ) | |
7 | 5, 6 | addcld 10649 | . . . . . . . . . 10 ⊢ (𝜑 → (𝐴 + 𝐵) ∈ ℂ) |
8 | 7 | halfcld 11870 | . . . . . . . . 9 ⊢ (𝜑 → ((𝐴 + 𝐵) / 2) ∈ ℂ) |
9 | 4, 8 | eqeltrd 2890 | . . . . . . . 8 ⊢ (𝜑 → 𝑀 ∈ ℂ) |
10 | 3, 9 | subcld 10986 | . . . . . . 7 ⊢ (𝜑 → (𝑄 − 𝑀) ∈ ℂ) |
11 | chordthmlem.QneM | . . . . . . . 8 ⊢ (𝜑 → 𝑄 ≠ 𝑀) | |
12 | 3, 9, 11 | subne0d 10995 | . . . . . . 7 ⊢ (𝜑 → (𝑄 − 𝑀) ≠ 0) |
13 | 6, 9 | subcld 10986 | . . . . . . 7 ⊢ (𝜑 → (𝐵 − 𝑀) ∈ ℂ) |
14 | 4 | oveq1d 7150 | . . . . . . . . . . . . . 14 ⊢ (𝜑 → (𝑀 · 2) = (((𝐴 + 𝐵) / 2) · 2)) |
15 | 9 | times2d 11869 | . . . . . . . . . . . . . 14 ⊢ (𝜑 → (𝑀 · 2) = (𝑀 + 𝑀)) |
16 | 2cnd 11703 | . . . . . . . . . . . . . . 15 ⊢ (𝜑 → 2 ∈ ℂ) | |
17 | 2ne0 11729 | . . . . . . . . . . . . . . . 16 ⊢ 2 ≠ 0 | |
18 | 17 | a1i 11 | . . . . . . . . . . . . . . 15 ⊢ (𝜑 → 2 ≠ 0) |
19 | 7, 16, 18 | divcan1d 11406 | . . . . . . . . . . . . . 14 ⊢ (𝜑 → (((𝐴 + 𝐵) / 2) · 2) = (𝐴 + 𝐵)) |
20 | 14, 15, 19 | 3eqtr3d 2841 | . . . . . . . . . . . . 13 ⊢ (𝜑 → (𝑀 + 𝑀) = (𝐴 + 𝐵)) |
21 | chordthmlem.AneB | . . . . . . . . . . . . . 14 ⊢ (𝜑 → 𝐴 ≠ 𝐵) | |
22 | 5, 6, 6, 21 | addneintr2d 10837 | . . . . . . . . . . . . 13 ⊢ (𝜑 → (𝐴 + 𝐵) ≠ (𝐵 + 𝐵)) |
23 | 20, 22 | eqnetrd 3054 | . . . . . . . . . . . 12 ⊢ (𝜑 → (𝑀 + 𝑀) ≠ (𝐵 + 𝐵)) |
24 | 23 | neneqd 2992 | . . . . . . . . . . 11 ⊢ (𝜑 → ¬ (𝑀 + 𝑀) = (𝐵 + 𝐵)) |
25 | oveq12 7144 | . . . . . . . . . . . 12 ⊢ ((𝑀 = 𝐵 ∧ 𝑀 = 𝐵) → (𝑀 + 𝑀) = (𝐵 + 𝐵)) | |
26 | 25 | anidms 570 | . . . . . . . . . . 11 ⊢ (𝑀 = 𝐵 → (𝑀 + 𝑀) = (𝐵 + 𝐵)) |
27 | 24, 26 | nsyl 142 | . . . . . . . . . 10 ⊢ (𝜑 → ¬ 𝑀 = 𝐵) |
28 | 27 | neqned 2994 | . . . . . . . . 9 ⊢ (𝜑 → 𝑀 ≠ 𝐵) |
29 | 28 | necomd 3042 | . . . . . . . 8 ⊢ (𝜑 → 𝐵 ≠ 𝑀) |
30 | 6, 9, 29 | subne0d 10995 | . . . . . . 7 ⊢ (𝜑 → (𝐵 − 𝑀) ≠ 0) |
31 | 2, 10, 12, 13, 30 | angcld 25391 | . . . . . 6 ⊢ (𝜑 → ((𝑄 − 𝑀)𝐹(𝐵 − 𝑀)) ∈ (-π(,]π)) |
32 | 1, 31 | sseldi 3913 | . . . . 5 ⊢ (𝜑 → ((𝑄 − 𝑀)𝐹(𝐵 − 𝑀)) ∈ ℝ) |
33 | 32 | recnd 10658 | . . . 4 ⊢ (𝜑 → ((𝑄 − 𝑀)𝐹(𝐵 − 𝑀)) ∈ ℂ) |
34 | 33 | coscld 15476 | . . 3 ⊢ (𝜑 → (cos‘((𝑄 − 𝑀)𝐹(𝐵 − 𝑀))) ∈ ℂ) |
35 | 6, 9 | negsubdi2d 11002 | . . . . . . 7 ⊢ (𝜑 → -(𝐵 − 𝑀) = (𝑀 − 𝐵)) |
36 | 9, 9, 5, 6 | addsubeq4d 11037 | . . . . . . . 8 ⊢ (𝜑 → ((𝑀 + 𝑀) = (𝐴 + 𝐵) ↔ (𝐴 − 𝑀) = (𝑀 − 𝐵))) |
37 | 20, 36 | mpbid 235 | . . . . . . 7 ⊢ (𝜑 → (𝐴 − 𝑀) = (𝑀 − 𝐵)) |
38 | 35, 37 | eqtr4d 2836 | . . . . . 6 ⊢ (𝜑 → -(𝐵 − 𝑀) = (𝐴 − 𝑀)) |
39 | 38 | oveq2d 7151 | . . . . 5 ⊢ (𝜑 → ((𝑄 − 𝑀)𝐹-(𝐵 − 𝑀)) = ((𝑄 − 𝑀)𝐹(𝐴 − 𝑀))) |
40 | 39 | fveq2d 6649 | . . . 4 ⊢ (𝜑 → (cos‘((𝑄 − 𝑀)𝐹-(𝐵 − 𝑀))) = (cos‘((𝑄 − 𝑀)𝐹(𝐴 − 𝑀)))) |
41 | 2, 10, 12, 13, 30 | cosangneg2d 25393 | . . . 4 ⊢ (𝜑 → (cos‘((𝑄 − 𝑀)𝐹-(𝐵 − 𝑀))) = -(cos‘((𝑄 − 𝑀)𝐹(𝐵 − 𝑀)))) |
42 | 5, 5, 6, 21 | addneintrd 10836 | . . . . . . . . . 10 ⊢ (𝜑 → (𝐴 + 𝐴) ≠ (𝐴 + 𝐵)) |
43 | 42, 20 | neeqtrrd 3061 | . . . . . . . . 9 ⊢ (𝜑 → (𝐴 + 𝐴) ≠ (𝑀 + 𝑀)) |
44 | 43 | necomd 3042 | . . . . . . . 8 ⊢ (𝜑 → (𝑀 + 𝑀) ≠ (𝐴 + 𝐴)) |
45 | 44 | neneqd 2992 | . . . . . . 7 ⊢ (𝜑 → ¬ (𝑀 + 𝑀) = (𝐴 + 𝐴)) |
46 | oveq12 7144 | . . . . . . . 8 ⊢ ((𝑀 = 𝐴 ∧ 𝑀 = 𝐴) → (𝑀 + 𝑀) = (𝐴 + 𝐴)) | |
47 | 46 | anidms 570 | . . . . . . 7 ⊢ (𝑀 = 𝐴 → (𝑀 + 𝑀) = (𝐴 + 𝐴)) |
48 | 45, 47 | nsyl 142 | . . . . . 6 ⊢ (𝜑 → ¬ 𝑀 = 𝐴) |
49 | 48 | neqned 2994 | . . . . 5 ⊢ (𝜑 → 𝑀 ≠ 𝐴) |
50 | eqidd 2799 | . . . . 5 ⊢ (𝜑 → (abs‘(𝑄 − 𝑀)) = (abs‘(𝑄 − 𝑀))) | |
51 | 5, 9 | subcld 10986 | . . . . . . 7 ⊢ (𝜑 → (𝐴 − 𝑀) ∈ ℂ) |
52 | 51 | absnegd 14801 | . . . . . 6 ⊢ (𝜑 → (abs‘-(𝐴 − 𝑀)) = (abs‘(𝐴 − 𝑀))) |
53 | 5, 9 | negsubdi2d 11002 | . . . . . . 7 ⊢ (𝜑 → -(𝐴 − 𝑀) = (𝑀 − 𝐴)) |
54 | 53 | fveq2d 6649 | . . . . . 6 ⊢ (𝜑 → (abs‘-(𝐴 − 𝑀)) = (abs‘(𝑀 − 𝐴))) |
55 | 37 | fveq2d 6649 | . . . . . 6 ⊢ (𝜑 → (abs‘(𝐴 − 𝑀)) = (abs‘(𝑀 − 𝐵))) |
56 | 52, 54, 55 | 3eqtr3d 2841 | . . . . 5 ⊢ (𝜑 → (abs‘(𝑀 − 𝐴)) = (abs‘(𝑀 − 𝐵))) |
57 | chordthmlem.ABequidistQ | . . . . 5 ⊢ (𝜑 → (abs‘(𝐴 − 𝑄)) = (abs‘(𝐵 − 𝑄))) | |
58 | 2, 3, 9, 5, 3, 9, 6, 11, 49, 11, 28, 50, 56, 57 | ssscongptld 25408 | . . . 4 ⊢ (𝜑 → (cos‘((𝑄 − 𝑀)𝐹(𝐴 − 𝑀))) = (cos‘((𝑄 − 𝑀)𝐹(𝐵 − 𝑀)))) |
59 | 40, 41, 58 | 3eqtr3rd 2842 | . . 3 ⊢ (𝜑 → (cos‘((𝑄 − 𝑀)𝐹(𝐵 − 𝑀))) = -(cos‘((𝑄 − 𝑀)𝐹(𝐵 − 𝑀)))) |
60 | 34, 59 | eqnegad 11351 | . 2 ⊢ (𝜑 → (cos‘((𝑄 − 𝑀)𝐹(𝐵 − 𝑀))) = 0) |
61 | coseq0negpitopi 25096 | . . 3 ⊢ (((𝑄 − 𝑀)𝐹(𝐵 − 𝑀)) ∈ (-π(,]π) → ((cos‘((𝑄 − 𝑀)𝐹(𝐵 − 𝑀))) = 0 ↔ ((𝑄 − 𝑀)𝐹(𝐵 − 𝑀)) ∈ {(π / 2), -(π / 2)})) | |
62 | 31, 61 | syl 17 | . 2 ⊢ (𝜑 → ((cos‘((𝑄 − 𝑀)𝐹(𝐵 − 𝑀))) = 0 ↔ ((𝑄 − 𝑀)𝐹(𝐵 − 𝑀)) ∈ {(π / 2), -(π / 2)})) |
63 | 60, 62 | mpbid 235 | 1 ⊢ (𝜑 → ((𝑄 − 𝑀)𝐹(𝐵 − 𝑀)) ∈ {(π / 2), -(π / 2)}) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 209 = wceq 1538 ∈ wcel 2111 ≠ wne 2987 ∖ cdif 3878 {csn 4525 {cpr 4527 ‘cfv 6324 (class class class)co 7135 ∈ cmpo 7137 ℂcc 10524 ℝcr 10525 0cc0 10526 + caddc 10529 · cmul 10531 − cmin 10859 -cneg 10860 / cdiv 11286 2c2 11680 (,]cioc 12727 ℑcim 14449 abscabs 14585 cosccos 15410 πcpi 15412 logclog 25146 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1797 ax-4 1811 ax-5 1911 ax-6 1970 ax-7 2015 ax-8 2113 ax-9 2121 ax-10 2142 ax-11 2158 ax-12 2175 ax-ext 2770 ax-rep 5154 ax-sep 5167 ax-nul 5174 ax-pow 5231 ax-pr 5295 ax-un 7441 ax-inf2 9088 ax-cnex 10582 ax-resscn 10583 ax-1cn 10584 ax-icn 10585 ax-addcl 10586 ax-addrcl 10587 ax-mulcl 10588 ax-mulrcl 10589 ax-mulcom 10590 ax-addass 10591 ax-mulass 10592 ax-distr 10593 ax-i2m1 10594 ax-1ne0 10595 ax-1rid 10596 ax-rnegex 10597 ax-rrecex 10598 ax-cnre 10599 ax-pre-lttri 10600 ax-pre-lttrn 10601 ax-pre-ltadd 10602 ax-pre-mulgt0 10603 ax-pre-sup 10604 ax-addf 10605 ax-mulf 10606 |
This theorem depends on definitions: df-bi 210 df-an 400 df-or 845 df-3or 1085 df-3an 1086 df-tru 1541 df-fal 1551 df-ex 1782 df-nf 1786 df-sb 2070 df-mo 2598 df-eu 2629 df-clab 2777 df-cleq 2791 df-clel 2870 df-nfc 2938 df-ne 2988 df-nel 3092 df-ral 3111 df-rex 3112 df-reu 3113 df-rmo 3114 df-rab 3115 df-v 3443 df-sbc 3721 df-csb 3829 df-dif 3884 df-un 3886 df-in 3888 df-ss 3898 df-pss 3900 df-nul 4244 df-if 4426 df-pw 4499 df-sn 4526 df-pr 4528 df-tp 4530 df-op 4532 df-uni 4801 df-int 4839 df-iun 4883 df-iin 4884 df-br 5031 df-opab 5093 df-mpt 5111 df-tr 5137 df-id 5425 df-eprel 5430 df-po 5438 df-so 5439 df-fr 5478 df-se 5479 df-we 5480 df-xp 5525 df-rel 5526 df-cnv 5527 df-co 5528 df-dm 5529 df-rn 5530 df-res 5531 df-ima 5532 df-pred 6116 df-ord 6162 df-on 6163 df-lim 6164 df-suc 6165 df-iota 6283 df-fun 6326 df-fn 6327 df-f 6328 df-f1 6329 df-fo 6330 df-f1o 6331 df-fv 6332 df-isom 6333 df-riota 7093 df-ov 7138 df-oprab 7139 df-mpo 7140 df-of 7389 df-om 7561 df-1st 7671 df-2nd 7672 df-supp 7814 df-wrecs 7930 df-recs 7991 df-rdg 8029 df-1o 8085 df-2o 8086 df-oadd 8089 df-er 8272 df-map 8391 df-pm 8392 df-ixp 8445 df-en 8493 df-dom 8494 df-sdom 8495 df-fin 8496 df-fsupp 8818 df-fi 8859 df-sup 8890 df-inf 8891 df-oi 8958 df-card 9352 df-pnf 10666 df-mnf 10667 df-xr 10668 df-ltxr 10669 df-le 10670 df-sub 10861 df-neg 10862 df-div 11287 df-nn 11626 df-2 11688 df-3 11689 df-4 11690 df-5 11691 df-6 11692 df-7 11693 df-8 11694 df-9 11695 df-n0 11886 df-z 11970 df-dec 12087 df-uz 12232 df-q 12337 df-rp 12378 df-xneg 12495 df-xadd 12496 df-xmul 12497 df-ioo 12730 df-ioc 12731 df-ico 12732 df-icc 12733 df-fz 12886 df-fzo 13029 df-fl 13157 df-mod 13233 df-seq 13365 df-exp 13426 df-fac 13630 df-bc 13659 df-hash 13687 df-shft 14418 df-cj 14450 df-re 14451 df-im 14452 df-sqrt 14586 df-abs 14587 df-limsup 14820 df-clim 14837 df-rlim 14838 df-sum 15035 df-ef 15413 df-sin 15415 df-cos 15416 df-pi 15418 df-struct 16477 df-ndx 16478 df-slot 16479 df-base 16481 df-sets 16482 df-ress 16483 df-plusg 16570 df-mulr 16571 df-starv 16572 df-sca 16573 df-vsca 16574 df-ip 16575 df-tset 16576 df-ple 16577 df-ds 16579 df-unif 16580 df-hom 16581 df-cco 16582 df-rest 16688 df-topn 16689 df-0g 16707 df-gsum 16708 df-topgen 16709 df-pt 16710 df-prds 16713 df-xrs 16767 df-qtop 16772 df-imas 16773 df-xps 16775 df-mre 16849 df-mrc 16850 df-acs 16852 df-mgm 17844 df-sgrp 17893 df-mnd 17904 df-submnd 17949 df-mulg 18217 df-cntz 18439 df-cmn 18900 df-psmet 20083 df-xmet 20084 df-met 20085 df-bl 20086 df-mopn 20087 df-fbas 20088 df-fg 20089 df-cnfld 20092 df-top 21499 df-topon 21516 df-topsp 21538 df-bases 21551 df-cld 21624 df-ntr 21625 df-cls 21626 df-nei 21703 df-lp 21741 df-perf 21742 df-cn 21832 df-cnp 21833 df-haus 21920 df-tx 22167 df-hmeo 22360 df-fil 22451 df-fm 22543 df-flim 22544 df-flf 22545 df-xms 22927 df-ms 22928 df-tms 22929 df-cncf 23483 df-limc 24469 df-dv 24470 df-log 25148 |
This theorem is referenced by: chordthmlem2 25419 |
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