Algebra question

Question

if f(x) = (x + 2)^2 – 1, what is the largest possible domain of f so that its inverse is also a function? explain by steps

Answer 1

Either (-∞,-2] or [-2,∞) will suffice.

On the negative interval the function is strictly decreasing and on the positive interval it is strictly increasing so that in either interval the inverse will be a function.