Chapter 10 - Compositions, Inverses, and Combinations of Functions - 10.2 Invertibility and Properties of Inverse Functions - Exercises and Problems for Section 10.2 - Exercises and Problems - Page 411: 39

$$y=4,\:y=\frac{4x^2-12x+9}{x^2+2x+1}$$

Switching the elements of the domain and the range (in other words, the dependent and independent variables), we find that the inverse is: $$y=\frac{\left(3-\sqrt{x}\right)\left(2-\sqrt{x}\right)}{4-x}\\ x=\frac{\left(3-\sqrt{y}\right)\left(2-\sqrt{y}\right)}{4-y} \\ y=4,\:y=\frac{4x^2-12x+9}{x^2+2x+1}$$