Answers

2014-01-24T00:21:17+08:00
∫cos^2 2x dx

formula:
case III
cos^2 x dx = (1/2 - cos2x/2) dx

=
∫(1/2 - cos (2)(2x)/2) dx
=(1/2)
∫dx - (1/2)∫cos4x dx
                 where :
               (1/2)(1/4)
∫cos4x 4dx

=1/2 x - 1/8 sin4x + C
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