let r, e be Real; ( 0 < r & 0 < e implies ex n being Nat st
for m being Nat st n <= m holds
for x, s being Real st x in ].(- r),r.[ & 0 < s & s < 1 holds
( |.(((((diff (sin,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| < e & |.(((((diff (cos,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| < e ) )
assume that
A1:
r > 0
and
A2:
e > 0
; ex n being Nat st
for m being Nat st n <= m holds
for x, s being Real st x in ].(- r),r.[ & 0 < s & s < 1 holds
( |.(((((diff (sin,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| < e & |.(((((diff (cos,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| < e )
consider r1, r2 being Real such that
A3:
( r1 >= 0 & r2 >= 0 )
and
A4:
for n being Nat
for x, s being Real st x in ].(- r),r.[ & 0 < s & s < 1 holds
( |.(((((diff (sin,].(- r),r.[)) . n) . (s * x)) * (x |^ n)) / (n !)).| <= (r1 * (r2 |^ n)) / (n !) & |.(((((diff (cos,].(- r),r.[)) . n) . (s * x)) * (x |^ n)) / (n !)).| <= (r1 * (r2 |^ n)) / (n !) )
by A1, Th22;
consider n being Nat such that
A5:
for m being Nat st n <= m holds
(r1 * (r2 |^ m)) / (m !) < e
by A2, A3, Th12;
take
n
; for m being Nat st n <= m holds
for x, s being Real st x in ].(- r),r.[ & 0 < s & s < 1 holds
( |.(((((diff (sin,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| < e & |.(((((diff (cos,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| < e )
let m be Nat; ( n <= m implies for x, s being Real st x in ].(- r),r.[ & 0 < s & s < 1 holds
( |.(((((diff (sin,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| < e & |.(((((diff (cos,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| < e ) )
assume
n <= m
; for x, s being Real st x in ].(- r),r.[ & 0 < s & s < 1 holds
( |.(((((diff (sin,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| < e & |.(((((diff (cos,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| < e )
then A6:
(r1 * (r2 |^ m)) / (m !) < e
by A5;
let x, s be Real; ( x in ].(- r),r.[ & 0 < s & s < 1 implies ( |.(((((diff (sin,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| < e & |.(((((diff (cos,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| < e ) )
assume
( x in ].(- r),r.[ & 0 < s & s < 1 )
; ( |.(((((diff (sin,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| < e & |.(((((diff (cos,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| < e )
then
( |.(((((diff (sin,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| <= (r1 * (r2 |^ m)) / (m !) & |.(((((diff (cos,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| <= (r1 * (r2 |^ m)) / (m !) )
by A4;
hence
( |.(((((diff (sin,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| < e & |.(((((diff (cos,].(- r),r.[)) . m) . (s * x)) * (x |^ m)) / (m !)).| < e )
by A6, XXREAL_0:2; verum