Posted by Rin on Tuesday, December 13, 2011 at 6:03pm.
By expressing 3x as (2x + x) prove that
cos3x = 4cos^3x  3cosx

trig  Reiny, Tuesday, December 13, 2011 at 6:23pm
check previous post of same question
Posted by Rin on Tuesday, December 13, 2011 at 6:03pm.
By expressing 3x as (2x + x) prove that
cos3x = 4cos^3x  3cosx
check previous post of same question