17 Apr
2015
17 Apr
'15
9:05 a.m.
sin(x) = 2 cos(x/2) sin(x/2) = 4 cos(x/2) cos(x/4) sin(x/4) = 2^n cos(x/2) ... cos(x/2^n) sin(x/2^n). In the limit, 2^n sin(x/2^n) = x. -- Gene From: David Wilson <davidwwilson@comcast.net> To: 'math-fun' <math-fun@mailman.xmission.com> Sent: Thursday, April 16, 2015 8:23 PM Subject: [math-fun] What's the proof? x*cos(x/2)*cos(x/4)*cos(x/8)*. = sin(x).