Hello everyone. I'm wondering if i'm allowed to use a counter example to disprove this. I'm not sure if i'm understanding the statement correctly though. THe directions are:(adsbygoogle = window.adsbygoogle || []).push({});

Determine whether the statement is true or false. Justify your answer with a rpoof or a counterexample.

Here is the question:

FOr all integers n, if n is prime then (-1)^n = -1.

If it says for ALL integers n, doesn't this mean negatives as well? If it said for All positive integers than wouldn't it be true? But if i let n = -1, i would get (-1)^(-1) = 1, not -1. But if they said, for all integers n, if n is prime..does this mean they are saying n > 1?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Proof for al integers n, if n is prime then (-1)^n = -1, can i use counter example?

**Physics Forums | Science Articles, Homework Help, Discussion**