Metamath Proof Explorer


Theorem asinsinlem

Description: Lemma for asinsin . (Contributed by Mario Carneiro, 2-Apr-2015)

Ref Expression
Assertion asinsinlem A A π 2 π 2 0 < e i A

Proof

Step Hyp Ref Expression
1 ax-icn i
2 simpl A A π 2 π 2 A
3 mulcl i A i A
4 1 2 3 sylancr A A π 2 π 2 i A
5 4 recld A A π 2 π 2 i A
6 5 reefcld A A π 2 π 2 e i A
7 neghalfpirx π 2 *
8 halfpire π 2
9 8 rexri π 2 *
10 elioo2 π 2 * π 2 * A π 2 π 2 A π 2 < A A < π 2
11 7 9 10 mp2an A π 2 π 2 A π 2 < A A < π 2
12 11 bilani A A π 2 π 2 A π 2 < A A < π 2
13 12 simp1d A A π 2 π 2 A
14 13 recoscld A A π 2 π 2 cos A
15 efgt0 i A 0 < e i A
16 5 15 syl A A π 2 π 2 0 < e i A
17 cosq14gt0 A π 2 π 2 0 < cos A
18 17 adantl A A π 2 π 2 0 < cos A
19 6 14 16 18 mulgt0d A A π 2 π 2 0 < e i A cos A
20 efeul i A e i A = e i A cos i A + i sin i A
21 4 20 syl A A π 2 π 2 e i A = e i A cos i A + i sin i A
22 21 fveq2d A A π 2 π 2 e i A = e i A cos i A + i sin i A
23 4 imcld A A π 2 π 2 i A
24 23 recoscld A A π 2 π 2 cos i A
25 24 recnd A A π 2 π 2 cos i A
26 23 resincld A A π 2 π 2 sin i A
27 26 recnd A A π 2 π 2 sin i A
28 mulcl i sin i A i sin i A
29 1 27 28 sylancr A A π 2 π 2 i sin i A
30 25 29 addcld A A π 2 π 2 cos i A + i sin i A
31 6 30 remul2d A A π 2 π 2 e i A cos i A + i sin i A = e i A cos i A + i sin i A
32 24 26 crred A A π 2 π 2 cos i A + i sin i A = cos i A
33 imre i A i A = i i A
34 4 33 syl A A π 2 π 2 i A = i i A
35 1 1 mulneg1i i i = i i
36 ixi i i = 1
37 36 negeqi i i = -1
38 negneg1e1 -1 = 1
39 35 37 38 3eqtri i i = 1
40 39 oveq1i i i A = 1 A
41 negicn i
42 41 a1i A A π 2 π 2 i
43 1 a1i A A π 2 π 2 i
44 42 43 2 mulassd A A π 2 π 2 i i A = i i A
45 mullid A 1 A = A
46 45 adantr A A π 2 π 2 1 A = A
47 40 44 46 3eqtr3a A A π 2 π 2 i i A = A
48 47 fveq2d A A π 2 π 2 i i A = A
49 34 48 eqtrd A A π 2 π 2 i A = A
50 49 fveq2d A A π 2 π 2 cos i A = cos A
51 32 50 eqtrd A A π 2 π 2 cos i A + i sin i A = cos A
52 51 oveq2d A A π 2 π 2 e i A cos i A + i sin i A = e i A cos A
53 22 31 52 3eqtrd A A π 2 π 2 e i A = e i A cos A
54 19 53 breqtrrd A A π 2 π 2 0 < e i A