Which of the following statements are TRUE about negative exponents?
a−n=−ana^{-n} = -a^na−n=−an for any nonzero aaa and positive integer nnn
a−n=1ana^{-n} = \frac{1}{a^n}a−n=an1 for any nonzero aaa and positive integer nnn
(ab)−n=a−n⋅b−n(ab)^{-n} = a^{-n} \cdot b^{-n}(ab)−n=a−n⋅b−n for nonzero a,ba, ba,b
1a−n=an\frac{1}{a^{-n}} = a^{n}a−n1=an for any nonzero aaa