Question

Find the domain of f(x) = ln(7 - x^2)/2 So I solve for this inequality, because the argument of the natural log must be strictly greater than 0. 7 - x^2 > 0 7 > x^2 \sqrt{7} > \sqrt{x^2} <=> \sqrt{7} > |x| Which in interval notation, is: ( -\sqrt{7}, \sqrt{7} ) But this is "wrong" for some reason. Would someone point out why please?