:: SIN_COS4 semantic presentation

definition
let c1 be real number ;
func tan c1 -> Real equals :: SIN_COS4:def 1
(sin a1) / (cos a1);
correctness
coherence
(sin c1) / (cos c1) is Real
;
by XREAL_0:def 1;
end;

:: deftheorem Def1 defines tan SIN_COS4:def 1 :
for b1 being real number holds tan b1 = (sin b1) / (cos b1);

definition
let c1 be real number ;
func cot c1 -> Real equals :: SIN_COS4:def 2
(cos a1) / (sin a1);
correctness
coherence
(cos c1) / (sin c1) is Real
;
by XREAL_0:def 1;
end;

:: deftheorem Def2 defines cot SIN_COS4:def 2 :
for b1 being real number holds cot b1 = (cos b1) / (sin b1);

definition
let c1 be real number ;
func cosec c1 -> Real equals :: SIN_COS4:def 3
1 / (sin a1);
correctness
coherence
1 / (sin c1) is Real
;
by XREAL_0:def 1;
end;

:: deftheorem Def3 defines cosec SIN_COS4:def 3 :
for b1 being real number holds cosec b1 = 1 / (sin b1);

definition
let c1 be real number ;
func sec c1 -> Real equals :: SIN_COS4:def 4
1 / (cos a1);
correctness
coherence
1 / (cos c1) is Real
;
by XREAL_0:def 1;
end;

:: deftheorem Def4 defines sec SIN_COS4:def 4 :
for b1 being real number holds sec b1 = 1 / (cos b1);

theorem Th1: :: SIN_COS4:1
for b1 being real number holds tan b1 = 1 / (cot b1) by XCMPLX_1:57;

theorem Th2: :: SIN_COS4:2
for b1 being real number holds tan (- b1) = - (tan b1)
proof end;

theorem Th3: :: SIN_COS4:3
for b1 being real number holds cosec (- b1) = - (1 / (sin b1))
proof end;

theorem Th4: :: SIN_COS4:4
for b1 being real number holds cot (- b1) = - (cot b1)
proof end;

theorem Th5: :: SIN_COS4:5
for b1 being real number st cos b1 <> 0 holds
(cos b1) * (sec b1) = 1 by XCMPLX_1:107;

theorem Th6: :: SIN_COS4:6
for b1 being real number holds (sin b1) * (sin b1) = 1 - ((cos b1) * (cos b1))
proof end;

theorem Th7: :: SIN_COS4:7
for b1 being real number holds (cos b1) * (cos b1) = 1 - ((sin b1) * (sin b1))
proof end;

theorem Th8: :: SIN_COS4:8
for b1 being real number st cos b1 <> 0 holds
sin b1 = (cos b1) * (tan b1)
proof end;

Lemma4: for b1, b2 being real number holds sin (b1 - b2) = ((sin b1) * (cos b2)) - ((cos b1) * (sin b2))
by COMPLEX2:4;

Lemma5: for b1, b2 being real number holds cos (b1 - b2) = ((cos b1) * (cos b2)) + ((sin b1) * (sin b2))
by COMPLEX2:4;

theorem Th9: :: SIN_COS4:9
canceled;

theorem Th10: :: SIN_COS4:10
canceled;

theorem Th11: :: SIN_COS4:11
for b1, b2 being real number st cos b1 <> 0 & cos b2 <> 0 holds
tan (b1 + b2) = ((tan b1) + (tan b2)) / (1 - ((tan b1) * (tan b2)))
proof end;

theorem Th12: :: SIN_COS4:12
for b1, b2 being real number st cos b1 <> 0 & cos b2 <> 0 holds
tan (b1 - b2) = ((tan b1) - (tan b2)) / (1 + ((tan b1) * (tan b2)))
proof end;

theorem Th13: :: SIN_COS4:13
for b1, b2 being real number st sin b1 <> 0 & sin b2 <> 0 holds
cot (b1 + b2) = (((cot b1) * (cot b2)) - 1) / ((cot b2) + (cot b1))
proof end;

theorem Th14: :: SIN_COS4:14
for b1, b2 being real number st sin b1 <> 0 & sin b2 <> 0 holds
cot (b1 - b2) = (((cot b1) * (cot b2)) + 1) / ((cot b2) - (cot b1))
proof end;

theorem Th15: :: SIN_COS4:15
for b1, b2, b3 being real number st cos b1 <> 0 & cos b2 <> 0 & cos b3 <> 0 holds
sin ((b1 + b2) + b3) = (((cos b1) * (cos b2)) * (cos b3)) * ((((tan b1) + (tan b2)) + (tan b3)) - (((tan b1) * (tan b2)) * (tan b3)))
proof end;

theorem Th16: :: SIN_COS4:16
for b1, b2, b3 being real number st cos b1 <> 0 & cos b2 <> 0 & cos b3 <> 0 holds
cos ((b1 + b2) + b3) = (((cos b1) * (cos b2)) * (cos b3)) * (((1 - ((tan b2) * (tan b3))) - ((tan b3) * (tan b1))) - ((tan b1) * (tan b2)))
proof end;

theorem Th17: :: SIN_COS4:17
for b1, b2, b3 being real number st cos b1 <> 0 & cos b2 <> 0 & cos b3 <> 0 holds
tan ((b1 + b2) + b3) = ((((tan b1) + (tan b2)) + (tan b3)) - (((tan b1) * (tan b2)) * (tan b3))) / (((1 - ((tan b2) * (tan b3))) - ((tan b3) * (tan b1))) - ((tan b1) * (tan b2)))
proof end;

theorem Th18: :: SIN_COS4:18
for b1, b2, b3 being real number st sin b1 <> 0 & sin b2 <> 0 & sin b3 <> 0 holds
cot ((b1 + b2) + b3) = ((((((cot b1) * (cot b2)) * (cot b3)) - (cot b1)) - (cot b2)) - (cot b3)) / (((((cot b2) * (cot b3)) + ((cot b3) * (cot b1))) + ((cot b1) * (cot b2))) - 1)
proof end;

theorem Th19: :: SIN_COS4:19
for b1, b2 being real number holds (sin b1) + (sin b2) = 2 * ((cos ((b1 - b2) / 2)) * (sin ((b1 + b2) / 2)))
proof end;

theorem Th20: :: SIN_COS4:20
for b1, b2 being real number holds (sin b1) - (sin b2) = 2 * ((cos ((b1 + b2) / 2)) * (sin ((b1 - b2) / 2)))
proof end;

theorem Th21: :: SIN_COS4:21
for b1, b2 being real number holds (cos b1) + (cos b2) = 2 * ((cos ((b1 + b2) / 2)) * (cos ((b1 - b2) / 2)))
proof end;

theorem Th22: :: SIN_COS4:22
for b1, b2 being real number holds (cos b1) - (cos b2) = - (2 * ((sin ((b1 + b2) / 2)) * (sin ((b1 - b2) / 2))))
proof end;

theorem Th23: :: SIN_COS4:23
for b1, b2 being real number st cos b1 <> 0 & cos b2 <> 0 holds
(tan b1) + (tan b2) = (sin (b1 + b2)) / ((cos b1) * (cos b2))
proof end;

theorem Th24: :: SIN_COS4:24
for b1, b2 being real number st cos b1 <> 0 & cos b2 <> 0 holds
(tan b1) - (tan b2) = (sin (b1 - b2)) / ((cos b1) * (cos b2))
proof end;

theorem Th25: :: SIN_COS4:25
for b1, b2 being real number st cos b1 <> 0 & sin b2 <> 0 holds
(tan b1) + (cot b2) = (cos (b1 - b2)) / ((cos b1) * (sin b2))
proof end;

theorem Th26: :: SIN_COS4:26
for b1, b2 being real number st cos b1 <> 0 & sin b2 <> 0 holds
(tan b1) - (cot b2) = - ((cos (b1 + b2)) / ((cos b1) * (sin b2)))
proof end;

theorem Th27: :: SIN_COS4:27
for b1, b2 being real number st sin b1 <> 0 & sin b2 <> 0 holds
(cot b1) + (cot b2) = (sin (b1 + b2)) / ((sin b1) * (sin b2))
proof end;

theorem Th28: :: SIN_COS4:28
for b1, b2 being real number st sin b1 <> 0 & sin b2 <> 0 holds
(cot b1) - (cot b2) = - ((sin (b1 - b2)) / ((sin b1) * (sin b2)))
proof end;

theorem Th29: :: SIN_COS4:29
for b1, b2 being real number holds (sin (b1 + b2)) + (sin (b1 - b2)) = 2 * ((sin b1) * (cos b2))
proof end;

theorem Th30: :: SIN_COS4:30
for b1, b2 being real number holds (sin (b1 + b2)) - (sin (b1 - b2)) = 2 * ((cos b1) * (sin b2))
proof end;

theorem Th31: :: SIN_COS4:31
for b1, b2 being real number holds (cos (b1 + b2)) + (cos (b1 - b2)) = 2 * ((cos b1) * (cos b2))
proof end;

theorem Th32: :: SIN_COS4:32
for b1, b2 being real number holds (cos (b1 + b2)) - (cos (b1 - b2)) = - (2 * ((sin b1) * (sin b2)))
proof end;

theorem Th33: :: SIN_COS4:33
for b1, b2 being real number holds (sin b1) * (sin b2) = - ((1 / 2) * ((cos (b1 + b2)) - (cos (b1 - b2))))
proof end;

theorem Th34: :: SIN_COS4:34
for b1, b2 being real number holds (sin b1) * (cos b2) = (1 / 2) * ((sin (b1 + b2)) + (sin (b1 - b2)))
proof end;

theorem Th35: :: SIN_COS4:35
for b1, b2 being real number holds (cos b1) * (sin b2) = (1 / 2) * ((sin (b1 + b2)) - (sin (b1 - b2)))
proof end;

theorem Th36: :: SIN_COS4:36
for b1, b2 being real number holds (cos b1) * (cos b2) = (1 / 2) * ((cos (b1 + b2)) + (cos (b1 - b2)))
proof end;

theorem Th37: :: SIN_COS4:37
for b1, b2, b3 being real number holds ((sin b1) * (sin b2)) * (sin b3) = (1 / 4) * ((((sin ((b1 + b2) - b3)) + (sin ((b2 + b3) - b1))) + (sin ((b3 + b1) - b2))) - (sin ((b1 + b2) + b3)))
proof end;

theorem Th38: :: SIN_COS4:38
for b1, b2, b3 being real number holds ((sin b1) * (sin b2)) * (cos b3) = (1 / 4) * ((((- (cos ((b1 + b2) - b3))) + (cos ((b2 + b3) - b1))) + (cos ((b3 + b1) - b2))) - (cos ((b1 + b2) + b3)))
proof end;

theorem Th39: :: SIN_COS4:39
for b1, b2, b3 being real number holds ((sin b1) * (cos b2)) * (cos b3) = (1 / 4) * ((((sin ((b1 + b2) - b3)) - (sin ((b2 + b3) - b1))) + (sin ((b3 + b1) - b2))) + (sin ((b1 + b2) + b3)))
proof end;

theorem Th40: :: SIN_COS4:40
for b1, b2, b3 being real number holds ((cos b1) * (cos b2)) * (cos b3) = (1 / 4) * ((((cos ((b1 + b2) - b3)) + (cos ((b2 + b3) - b1))) + (cos ((b3 + b1) - b2))) + (cos ((b1 + b2) + b3)))
proof end;

theorem Th41: :: SIN_COS4:41
for b1, b2 being real number holds (sin (b1 + b2)) * (sin (b1 - b2)) = ((sin b1) * (sin b1)) - ((sin b2) * (sin b2))
proof end;

theorem Th42: :: SIN_COS4:42
for b1, b2 being real number holds (sin (b1 + b2)) * (sin (b1 - b2)) = ((cos b2) * (cos b2)) - ((cos b1) * (cos b1))
proof end;

theorem Th43: :: SIN_COS4:43
for b1, b2 being real number holds (sin (b1 + b2)) * (cos (b1 - b2)) = ((sin b1) * (cos b1)) + ((sin b2) * (cos b2))
proof end;

theorem Th44: :: SIN_COS4:44
for b1, b2 being real number holds (cos (b1 + b2)) * (sin (b1 - b2)) = ((sin b1) * (cos b1)) - ((sin b2) * (cos b2))
proof end;

theorem Th45: :: SIN_COS4:45
for b1, b2 being real number holds (cos (b1 + b2)) * (cos (b1 - b2)) = ((cos b1) * (cos b1)) - ((sin b2) * (sin b2))
proof end;

theorem Th46: :: SIN_COS4:46
for b1, b2 being real number holds (cos (b1 + b2)) * (cos (b1 - b2)) = ((cos b2) * (cos b2)) - ((sin b1) * (sin b1))
proof end;

theorem Th47: :: SIN_COS4:47
for b1, b2 being real number st cos b1 <> 0 & cos b2 <> 0 holds
(sin (b1 + b2)) / (sin (b1 - b2)) = ((tan b1) + (tan b2)) / ((tan b1) - (tan b2))
proof end;

theorem Th48: :: SIN_COS4:48
for b1, b2 being real number st cos b1 <> 0 & cos b2 <> 0 holds
(cos (b1 + b2)) / (cos (b1 - b2)) = (1 - ((tan b1) * (tan b2))) / (1 + ((tan b1) * (tan b2)))
proof end;

theorem Th49: :: SIN_COS4:49
for b1, b2 being real number holds ((sin b1) + (sin b2)) / ((sin b1) - (sin b2)) = (tan ((b1 + b2) / 2)) * (cot ((b1 - b2) / 2))
proof end;

theorem Th50: :: SIN_COS4:50
for b1, b2 being real number st cos ((b1 - b2) / 2) <> 0 holds
((sin b1) + (sin b2)) / ((cos b1) + (cos b2)) = tan ((b1 + b2) / 2)
proof end;

theorem Th51: :: SIN_COS4:51
for b1, b2 being real number st cos ((b1 + b2) / 2) <> 0 holds
((sin b1) - (sin b2)) / ((cos b1) + (cos b2)) = tan ((b1 - b2) / 2)
proof end;

theorem Th52: :: SIN_COS4:52
for b1, b2 being real number st sin ((b1 + b2) / 2) <> 0 holds
((sin b1) + (sin b2)) / ((cos b2) - (cos b1)) = cot ((b1 - b2) / 2)
proof end;

theorem Th53: :: SIN_COS4:53
for b1, b2 being real number st sin ((b1 - b2) / 2) <> 0 holds
((sin b1) - (sin b2)) / ((cos b2) - (cos b1)) = cot ((b1 + b2) / 2)
proof end;

theorem Th54: :: SIN_COS4:54
for b1, b2 being real number holds ((cos b1) + (cos b2)) / ((cos b1) - (cos b2)) = (cot ((b1 + b2) / 2)) * (cot ((b2 - b1) / 2))
proof end;