In question 2e $ x(t)= \sum_{k=-\infty}^\infty \frac{1}{1+(x-7k)^2} \ $
should it be$ x(t)= \sum_{k=-\infty}^\infty \frac{1}{1+(t-7k)^2} \ $ ?
and I was trying to find out what the peak value is for this question but turns out to be very hard to calculate something like this$ \sum_{t=-\infty}^\infty \frac{1}{1+t^2} \ $ and wolfram said answer is π * coth(/pi). is there any easier way to do that?
Yimin. Jan 20
