Answer:
[tex]y = \frac{\sqrt{x+4} }{3}, \ y = -\frac{\sqrt{x+4} }{3}[/tex]
Step-by-step explanation:
To find inverse we replace and y first.
[tex]y = 9x^2 - 4 \ becomes \ x = 9y^2 -4[/tex]
[tex]Then \ solve \ for \ y\\\\9y^2 = x+ 4\\\\y^2 = \frac{x+4}{9}\\\\y = \pm \sqrt{\frac{x+4}{9}} \\\\y = \pm {\frac{\sqrt{x+4}}{3}[/tex]
