Write the set {-1/16, -1/8, -1/4, -1/2, 1/2, 1/4, 1/8, 1/16} in compact (i.e., concise) notation.

Question

I got it as the set {sqrt(1/4^x) : x Є Z - {0} }

Answer 1

Your answer is not correct. Note that the square root of a non-negative real number is non-negative.

Perhaps that$$\left\{\frac{(-1)^a}{2^b}\,\middle|\,(a,b)\in\{0,1\}\times\{1,2,3,4\}\right\}$$is what you're after.