RealiseNothing
what is that?It is Cowpea
Re: HSC 2013 4U Marathon
Subtracting the two gives:
Using this on each term in the series gives:
Now consider:
Taking the real part of this gives the sum of the cosines we need, so since I cbf evaluating the real part of this, your series is equal to:
First method I used was:Nice work guys,
Subtracting the two gives:
Using this on each term in the series gives:
Now consider:
Taking the real part of this gives the sum of the cosines we need, so since I cbf evaluating the real part of this, your series is equal to: