# Understanding covariance

I came across following problem:

A discrete random variable $$P$$ takes values $$-3,-2,0,2,3$$ with probability $$0.2$$. Let $$Q=P^2$$ be another random variable. What is covariance of $$P$$ and $$Q$$?

I solved it as follows:

P = -3, -2, 0, 2, 3    Mean = 0/0 = 0
Q =  9,  4, 0, 4, 9    Mean = 26/5 = 5.2

Covariance = ((-3)(3.8) + (-2)(-1.2) + (0)(-5.2) + (2)(-1.2) + (3)(3.8)) / 5
= 0 / 5
0

So I was guessing what does the covariance of zero here means. Does that mean that P and Q do not co-variate (deviate together) at all? Or my approach or calculations were incorrect?