f(0) ≠ 0
f(1) = 3
f(x) * f(y) = f(x+y) + f(x-y)
1. Determine f(7).
Thanks for the help!
Yes, I saw this post and tried to do it out myself out of pure curiosity but had problems trying to do it, which is why I am asking. I am curious how it is done. Could you please elaborate on your answer?