Let \(f(x) = (x+2)^2-5\). If the domain of \(f\) is all real numbers, then \(f\) does not have an inverse function, but if we restrict the domain of \(f\) to an interval \( [c,\infty)\), then \(f\) may have an inverse function. What is the smallest value of \(c\) we can use here, so that \(f\) does have an inverse function?
