Question

Z^m-n (z^m+ z^m+n + z^n)

Answer 1

Answer:Your left hand side evaluates to:

m+(−1)mn+(−1)m+(−1)mnp

and your right hand side evaluates to:

m+(−1)mn+(−1)m+np

After eliminating the common terms:

m+(−1)mn from both sides, we are left with showing:

(−1)m+(−1)mnp=(−1)m+np

If p=0, both sides are clearly equal, so assume p≠0, and we can (by cancellation) simply prove:

(−1)(−1)mn=(−1)n.

It should be clear that if m is even, we have equality (both sides are (−1)n), so we are down to the case where m is odd. In this case:

(−1)(−1)mn=(−1)−n=1(−1)n

Multiplying both sides by (−1)n then yields:

1=(−1)2n=[(−1)n]2 which is always true, no matter what n is