Answer: D
Step-by-step explanation:
If the equation is f(x) = 9x^2 -12, you can solve for the inverse by switching the x and y like this.
x = 9y^2-12.
Then you solve for y.
x = 9y^2-12.
x+12=9y^2
y^2=(x+12)/9
y=sqrt((x+12)/9)
y=sqrt((x+12))/3 which is D
