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Theorem abssinper 8707
Description: The absolute value of sine has period pi.
Assertion
Ref Expression
abssinper |- ((A e. CC /\ K e. ZZ) -> (abs`
(sin` (A + (K x. pi)))) = (abs` (sin` A)))

Proof of Theorem abssinper
StepHypRef Expression
1 zeot 6201 . . 3 |- (K e. ZZ -> ((K / 2) e. ZZ \/ ((K + 1) / 2) e. ZZ))
21adantl 390 . 2 |- ((A e. CC /\ K e. ZZ) -> ((K / 2) e. ZZ \/ ((K + 1) / 2) e. ZZ))
3 zcnt 6142 . . . . . . . . . . 11 |- (K e. ZZ -> K e. CC)
4 halfclt 6035 . . . . . . . . . . . . 13 |- (K e. CC -> (K / 2) e. CC)
5 2cn 5982 . . . . . . . . . . . . . 14 |- 2 e. CC
6 pire 8672 . . . . . . . . . . . . . . 15 |- pi e. RR
76recn 5326 . . . . . . . . . . . . . 14 |- pi e. CC
8 mulasst 5320 . . . . . . . . . . . . . 14 |- (((K / 2) e. CC /\ 2 e. CC /\ pi e. CC) -> (((K / 2) x. 2) x. pi) = ((K / 2) x. (2 x. pi)))
95, 7, 8mp3an23 910 . . . . . . . . . . . . 13 |- ((K / 2) e. CC -> (((K / 2) x. 2) x. pi) = ((K / 2) x. (2 x. pi)))
104, 9syl 10 . . . . . . . . . . . 12 |- (K e. CC -> (((K / 2) x. 2) x. pi) = ((K / 2) x. (2 x. pi)))
11 2ne0 5992 . . . . . . . . . . . . . 14 |- 2 =/= 0
12 divcan1t 5732 . . . . . . . . . . . . . 14 |- ((K e. CC /\ 2 e. CC /\ 2 =/= 0) -> ((K / 2) x. 2) = K)
135, 11, 12mp3an23 910 . . . . . . . . . . . . 13 |- (K e. CC -> ((K / 2) x. 2) = K)
1413opreq1d 3981 . . . . . . . . . . . 12 |- (K e. CC -> (((K / 2) x. 2) x. pi) = (K x. pi))
1510, 14eqtr3d 1512 . . . . . . . . . . 11 |- (K e. CC -> ((K / 2) x. (2 x. pi)) = (K x. pi))
163, 15syl 10 . . . . . . . . . 10 |- (K e. ZZ -> ((K / 2) x. (2 x. pi)) = (K x. pi))
1716adantl 390 . . . . . . . . 9 |- ((A e. CC /\ K e. ZZ) -> ((K / 2) x. (2 x. pi)) = (K x. pi))
1817opreq2d 3982 . . . . . . . 8 |- ((A e. CC /\ K e. ZZ) -> (A + ((K / 2) x. (2 x. pi))) = (A + (K x. pi)))
1918fveq2d 3734 . . . . . . 7 |- ((A e. CC /\ K e. ZZ) -> (sin`
(A + ((K / 2) x. (2 x. pi)))) = (sin` (A + (K x. pi))))
2019eqcomd 1483 . . . . . 6 |- ((A e. CC /\ K e. ZZ) -> (sin`
(A + (K x. pi))) = (sin` (A + ((K / 2) x. (2 x. pi)))))
2120adantr 391 . . . . 5 |- (((A e. CC /\ K e. ZZ) /\ (K / 2) e. ZZ) -> (sin` (A + (K x. pi))) = (sin` (A + ((K / 2) x. (2 x. pi)))))
22 sinper 8685 . . . . . 6 |- ((A e. CC /\ (K / 2) e. ZZ) -> (sin`
(A + ((K / 2) x. (2 x. pi)))) = (sin` A))
2322adantlr 395 . . . . 5 |- (((A e. CC /\ K e. ZZ) /\ (K / 2) e. ZZ) -> (sin` (A + ((K / 2) x. (2 x. pi)))) = (sin`
A))
2421, 23eqtrd 1510 . . . 4 |- (((A e. CC /\ K e. ZZ) /\ (K / 2) e. ZZ) -> (sin` (A + (K x. pi))) = (sin` A))
2524fveq2d 3734 . . 3 |- (((A e. CC /\ K e. ZZ) /\ (K / 2) e. ZZ) -> (abs` (sin` (A + (K x. pi)))) = (abs` (sin` A)))
26 subadd23t 5397 . . . . . . . . . . . 12 |- ((A e. CC /\ pi e. CC /\ (((K + 1) / 2) x. (2 x. pi)) e. CC) -> ((A - pi) + (((K + 1) / 2) x. (2 x. pi))) = (A + ((((K + 1) / 2) x. (2 x. pi)) - pi)))
277, 26mp3an2 906 . . . . . . . . . . 11 |- ((A e. CC /\ (((K + 1) / 2) x. (2 x. pi)) e. CC) -> ((A - pi) + (((K + 1) / 2) x. (2 x. pi))) = (A + ((((K + 1) / 2) x. (2 x. pi)) - pi)))
28 peano2cn 5356 . . . . . . . . . . . . 13 |- (K e. CC -> (K + 1) e. CC)
29 halfclt 6035 . . . . . . . . . . . . 13 |- ((K + 1) e. CC -> ((K + 1) / 2) e. CC)
3028, 29syl 10 . . . . . . . . . . . 12 |- (K e. CC -> ((K + 1) / 2) e. CC)
315, 7mulcl 5333 . . . . . . . . . . . . 13 |- (2 x. pi) e. CC
32 mulclt 5315 . . . . . . . . . . . . 13 |- ((((K + 1) / 2) e. CC /\ (2 x. pi) e. CC) -> (((K + 1) / 2) x. (2 x. pi)) e. CC)
3331, 32mpan2 698 . . . . . . . . . . . 12 |- (((K + 1) / 2) e. CC -> (((K + 1) / 2) x. (2 x. pi)) e. CC)
3430, 33syl 10 . . . . . . . . . . 11 |- (K e. CC -> (((K + 1) / 2) x. (2 x. pi)) e. CC)
3527, 34sylan2 453 . . . . . . . . . 10 |- ((A e. CC /\ K e. CC) -> ((A - pi) + (((K + 1) / 2) x. (2 x. pi))) = (A + ((((K + 1) / 2) x. (2 x. pi)) - pi)))
36 divcan1t 5732 . . . . . . . . . . . . . . . . . . 19 |- (((K + 1) e. CC /\ 2 e. CC /\ 2 =/= 0) -> (((K + 1) / 2) x. 2) = (K + 1))
375, 11, 36mp3an23 910 . . . . . . . . . . . . . . . . . 18 |- ((K + 1) e. CC -> (((K + 1) / 2) x. 2) = (K + 1))
3828, 37syl 10 . . . . . . . . . . . . . . . . 17 |- (K e. CC -> (((K + 1) / 2) x. 2) = (K + 1))
3938opreq1d 3981 . . . . . . . . . . . . . . . 16 |- (K e. CC -> ((((K + 1) / 2) x. 2) x. pi) = ((K + 1) x. pi))
40 ax1cn 5281 . . . . . . . . . . . . . . . . 17 |- 1 e. CC
41 adddirt 5331 . . . . . . . . . . . . . . . . 17 |- ((K e. CC /\ 1 e. CC /\ pi e. CC) -> ((K + 1) x. pi) = ((K x. pi) + (1 x. pi)))
4240, 7, 41mp3an23 910 . . . . . . . . . . . . . . . 16 |- (K e. CC -> ((K + 1) x. pi) = ((K x. pi) + (1 x. pi)))
437mulid2 5345 . . . . . . . . . . . . . . . . . 18 |- (1 x. pi) = pi
4443opreq2i 3978 . . . . . . . . . . . . . . . . 17 |- ((K x. pi) + (1 x. pi)) = ((K x. pi) + pi)
4544a1i 8 . . . . . . . . . . . . . . . 16 |- (K e. CC -> ((K x. pi) + (1 x. pi)) = ((K x. pi) + pi))
4639, 42, 453eqtrrd 1515 . . . . . . . . . . . . . . 15 |- (K e. CC -> ((K x. pi) + pi) = ((((K + 1) / 2) x. 2) x. pi))
47 mulasst 5320 . . . . . . . . . . . . . . . . 17 |- ((((K + 1) / 2) e. CC /\ 2 e. CC /\ pi e. CC) -> ((((K + 1) / 2) x. 2) x. pi) = (((K + 1) / 2) x. (2 x. pi)))
485, 7, 47mp3an23 910 . . . . . . . . . . . . . . . 16 |- (((K + 1) / 2) e. CC -> ((((K + 1) / 2) x. 2) x. pi) = (((K + 1) / 2) x. (2 x. pi)))
4930, 48syl 10 . . . . . . . . . . . . . . 15 |- (K e. CC -> ((((K + 1) / 2) x. 2) x. pi) = (((K + 1) / 2) x. (2 x. pi)))
5046, 49eqtr2d 1511 . . . . . . . . . . . . . 14 |- (K e. CC -> (((K + 1) / 2) x. (2 x. pi)) = ((K x. pi) + pi))
5150opreq1d 3981 . . . . . . . . . . . . 13 |- (K e. CC -> ((((K + 1) / 2) x. (2 x. pi)) - pi) = (((K x. pi) + pi) - pi))
52 mulclt 5315 . . . . . . . . . . . . . . 15 |- ((K e. CC /\ pi e. CC) -> (K x. pi) e. CC)
537, 52mpan2 698 . . . . . . . . . . . . . 14 |- (K e. CC -> (K x. pi) e. CC)
54 pncant 5409 . . . . . . . . . . . . . . 15 |- (((K x. pi) e. CC /\ pi e. CC) -> (((K x. pi) + pi) - pi) = (K x. pi))
557, 54mpan2 698 . . . . . . . . . . . . . 14 |- ((K x. pi) e. CC -> (((K x. pi) + pi) - pi) = (K x. pi))
5653, 55syl 10 . . . . . . . . . . . . 13 |- (K e. CC -> (((K x. pi) + pi) - pi) = (K x. pi))
5751, 56eqtrd 1510 . . . . . . . . . . . 12 |- (K e. CC -> ((((K + 1) / 2) x. (2 x. pi)) - pi) = (K x. pi))
5857adantl 390 . . . . . . . . . . 11 |- ((A e. CC /\ K e. CC) -> ((((K + 1) / 2) x. (2 x. pi)) - pi) = (K x. pi))
5958opreq2d 3982 . . . . . . . . . 10 |- ((A e. CC /\ K e. CC) -> (A + ((((K + 1) / 2) x. (2 x. pi)) - pi)) = (A + (K x. pi)))
6035, 59eqtr2d 1511 . . . . . . . . 9 |- ((A e. CC /\ K e. CC) -> (A + (K x. pi)) = ((A - pi) + (((K + 1) / 2) x. (2 x. pi))))
6160, 3sylan2 453 . . . . . . . 8 |- (