1. ## Polar Integral

I am having problems with this and was hoping somebody could assist. The polar function to integrate is:

cos^2 7t
cos^2 7t = 1/2(1+cos 14t)
1/4|(1+cos 14t)^2 dt
=1/4|1+2cos 14t+cos^2 14t dt
=1/4|1dt + 1/2|cos 14t dt + 1/8|1dt + 1/8|cos 28t dt
After evaluating this I get :-
3t/8+(8sin 14t+sin 28t)/224 +C.

t/2+(sin 14t)/28 + C

2. Originally Posted by p75213
I am having problems with this and was hoping somebody could assist. The polar function to integrate is:

cos^2 7t
cos^2 7t = 1/2(1+cos 14t)
1/4|(1+cos 14t)^2 dt
=1/4|1+2cos 14t+cos^2 14t dt
=1/4|1dt + 1/2|cos 14t dt + 1/8|1dt + 1/8|cos 28t dt
After evaluating this I get :-
3t/8+(8sin 14t+sin 28t)/224 +C.

t/2+(sin 14t)/28 + C
you want to integrate
$\displaystyle \int \cos ^2 7t \; dt$

or

$\displaystyle \int (\cos ^2 7t )^2 \; dt$

3. Originally Posted by p75213
I am having problems with this and was hoping somebody could assist. The polar function to integrate is:

cos^2 7t
cos^2 7t = 1/2(1+cos 14t)
1/4|(1+cos 14t)^2 dt
=1/4|1+2cos 14t+cos^2 14t dt
=1/4|1dt + 1/2|cos 14t dt + 1/8|1dt + 1/8|cos 28t dt
After evaluating this I get :-
3t/8+(8sin 14t+sin 28t)/224 +C.