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Mathbox for Glauco Siliprandi |
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Mirrors > Home > MPE Home > Th. List > Mathboxes > sinmulcos | Structured version Visualization version GIF version |
Description: Multiplication formula for sine and cosine. (Contributed by Glauco Siliprandi, 11-Dec-2019.) |
Ref | Expression |
---|---|
sinmulcos | β’ ((π΄ β β β§ π΅ β β) β ((sinβπ΄) Β· (cosβπ΅)) = (((sinβ(π΄ + π΅)) + (sinβ(π΄ β π΅))) / 2)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simpl 481 | . . . . . . 7 β’ ((π΄ β β β§ π΅ β β) β π΄ β β) | |
2 | 1 | sincld 16116 | . . . . . 6 β’ ((π΄ β β β§ π΅ β β) β (sinβπ΄) β β) |
3 | cosf 16111 | . . . . . . . 8 β’ cos:ββΆβ | |
4 | 3 | a1i 11 | . . . . . . 7 β’ (π΄ β β β cos:ββΆβ) |
5 | 4 | ffvelcdmda 7099 | . . . . . 6 β’ ((π΄ β β β§ π΅ β β) β (cosβπ΅) β β) |
6 | 2, 5 | mulcld 11274 | . . . . 5 β’ ((π΄ β β β§ π΅ β β) β ((sinβπ΄) Β· (cosβπ΅)) β β) |
7 | 1 | coscld 16117 | . . . . . 6 β’ ((π΄ β β β§ π΅ β β) β (cosβπ΄) β β) |
8 | sinf 16110 | . . . . . . . 8 β’ sin:ββΆβ | |
9 | 8 | a1i 11 | . . . . . . 7 β’ (π΄ β β β sin:ββΆβ) |
10 | 9 | ffvelcdmda 7099 | . . . . . 6 β’ ((π΄ β β β§ π΅ β β) β (sinβπ΅) β β) |
11 | 7, 10 | mulcld 11274 | . . . . 5 β’ ((π΄ β β β§ π΅ β β) β ((cosβπ΄) Β· (sinβπ΅)) β β) |
12 | 6, 11, 6 | ppncand 11651 | . . . 4 β’ ((π΄ β β β§ π΅ β β) β ((((sinβπ΄) Β· (cosβπ΅)) + ((cosβπ΄) Β· (sinβπ΅))) + (((sinβπ΄) Β· (cosβπ΅)) β ((cosβπ΄) Β· (sinβπ΅)))) = (((sinβπ΄) Β· (cosβπ΅)) + ((sinβπ΄) Β· (cosβπ΅)))) |
13 | sinadd 16150 | . . . . 5 β’ ((π΄ β β β§ π΅ β β) β (sinβ(π΄ + π΅)) = (((sinβπ΄) Β· (cosβπ΅)) + ((cosβπ΄) Β· (sinβπ΅)))) | |
14 | sinsub 16154 | . . . . 5 β’ ((π΄ β β β§ π΅ β β) β (sinβ(π΄ β π΅)) = (((sinβπ΄) Β· (cosβπ΅)) β ((cosβπ΄) Β· (sinβπ΅)))) | |
15 | 13, 14 | oveq12d 7444 | . . . 4 β’ ((π΄ β β β§ π΅ β β) β ((sinβ(π΄ + π΅)) + (sinβ(π΄ β π΅))) = ((((sinβπ΄) Β· (cosβπ΅)) + ((cosβπ΄) Β· (sinβπ΅))) + (((sinβπ΄) Β· (cosβπ΅)) β ((cosβπ΄) Β· (sinβπ΅))))) |
16 | 6 | 2timesd 12495 | . . . 4 β’ ((π΄ β β β§ π΅ β β) β (2 Β· ((sinβπ΄) Β· (cosβπ΅))) = (((sinβπ΄) Β· (cosβπ΅)) + ((sinβπ΄) Β· (cosβπ΅)))) |
17 | 12, 15, 16 | 3eqtr4d 2778 | . . 3 β’ ((π΄ β β β§ π΅ β β) β ((sinβ(π΄ + π΅)) + (sinβ(π΄ β π΅))) = (2 Β· ((sinβπ΄) Β· (cosβπ΅)))) |
18 | 17 | oveq1d 7441 | . 2 β’ ((π΄ β β β§ π΅ β β) β (((sinβ(π΄ + π΅)) + (sinβ(π΄ β π΅))) / 2) = ((2 Β· ((sinβπ΄) Β· (cosβπ΅))) / 2)) |
19 | 2cnd 12330 | . . 3 β’ ((π΄ β β β§ π΅ β β) β 2 β β) | |
20 | 2ne0 12356 | . . . 4 β’ 2 β 0 | |
21 | 20 | a1i 11 | . . 3 β’ ((π΄ β β β§ π΅ β β) β 2 β 0) |
22 | 6, 19, 21 | divcan3d 12035 | . 2 β’ ((π΄ β β β§ π΅ β β) β ((2 Β· ((sinβπ΄) Β· (cosβπ΅))) / 2) = ((sinβπ΄) Β· (cosβπ΅))) |
23 | 18, 22 | eqtr2d 2769 | 1 β’ ((π΄ β β β§ π΅ β β) β ((sinβπ΄) Β· (cosβπ΅)) = (((sinβ(π΄ + π΅)) + (sinβ(π΄ β π΅))) / 2)) |
Colors of variables: wff setvar class |
Syntax hints: β wi 4 β§ wa 394 = wceq 1533 β wcel 2098 β wne 2937 βΆwf 6549 βcfv 6553 (class class class)co 7426 βcc 11146 0cc0 11148 + caddc 11151 Β· cmul 11153 β cmin 11484 / cdiv 11911 2c2 12307 sincsin 16049 cosccos 16050 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1789 ax-4 1803 ax-5 1905 ax-6 1963 ax-7 2003 ax-8 2100 ax-9 2108 ax-10 2129 ax-11 2146 ax-12 2166 ax-ext 2699 ax-rep 5289 ax-sep 5303 ax-nul 5310 ax-pow 5369 ax-pr 5433 ax-un 7748 ax-inf2 9674 ax-cnex 11204 ax-resscn 11205 ax-1cn 11206 ax-icn 11207 ax-addcl 11208 ax-addrcl 11209 ax-mulcl 11210 ax-mulrcl 11211 ax-mulcom 11212 ax-addass 11213 ax-mulass 11214 ax-distr 11215 ax-i2m1 11216 ax-1ne0 11217 ax-1rid 11218 ax-rnegex 11219 ax-rrecex 11220 ax-cnre 11221 ax-pre-lttri 11222 ax-pre-lttrn 11223 ax-pre-ltadd 11224 ax-pre-mulgt0 11225 ax-pre-sup 11226 |
This theorem depends on definitions: df-bi 206 df-an 395 df-or 846 df-3or 1085 df-3an 1086 df-tru 1536 df-fal 1546 df-ex 1774 df-nf 1778 df-sb 2060 df-mo 2529 df-eu 2558 df-clab 2706 df-cleq 2720 df-clel 2806 df-nfc 2881 df-ne 2938 df-nel 3044 df-ral 3059 df-rex 3068 df-rmo 3374 df-reu 3375 df-rab 3431 df-v 3475 df-sbc 3779 df-csb 3895 df-dif 3952 df-un 3954 df-in 3956 df-ss 3966 df-pss 3968 df-nul 4327 df-if 4533 df-pw 4608 df-sn 4633 df-pr 4635 df-op 4639 df-uni 4913 df-int 4954 df-iun 5002 df-br 5153 df-opab 5215 df-mpt 5236 df-tr 5270 df-id 5580 df-eprel 5586 df-po 5594 df-so 5595 df-fr 5637 df-se 5638 df-we 5639 df-xp 5688 df-rel 5689 df-cnv 5690 df-co 5691 df-dm 5692 df-rn 5693 df-res 5694 df-ima 5695 df-pred 6310 df-ord 6377 df-on 6378 df-lim 6379 df-suc 6380 df-iota 6505 df-fun 6555 df-fn 6556 df-f 6557 df-f1 6558 df-fo 6559 df-f1o 6560 df-fv 6561 df-isom 6562 df-riota 7382 df-ov 7429 df-oprab 7430 df-mpo 7431 df-om 7879 df-1st 8001 df-2nd 8002 df-frecs 8295 df-wrecs 8326 df-recs 8400 df-rdg 8439 df-1o 8495 df-er 8733 df-pm 8856 df-en 8973 df-dom 8974 df-sdom 8975 df-fin 8976 df-sup 9475 df-inf 9476 df-oi 9543 df-card 9972 df-pnf 11290 df-mnf 11291 df-xr 11292 df-ltxr 11293 df-le 11294 df-sub 11486 df-neg 11487 df-div 11912 df-nn 12253 df-2 12315 df-3 12316 df-n0 12513 df-z 12599 df-uz 12863 df-rp 13017 df-ico 13372 df-fz 13527 df-fzo 13670 df-fl 13799 df-seq 14009 df-exp 14069 df-fac 14275 df-bc 14304 df-hash 14332 df-shft 15056 df-cj 15088 df-re 15089 df-im 15090 df-sqrt 15224 df-abs 15225 df-limsup 15457 df-clim 15474 df-rlim 15475 df-sum 15675 df-ef 16053 df-sin 16055 df-cos 16056 |
This theorem is referenced by: dirkertrigeqlem2 45534 |
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