Which equation is the inverse of y = 9x2 – 4?

To find the inverse of a function, we swap  and  so that we're effectively solving for  in terms of .we first isolate the  variable by adding  to both sides of the equation, finding that: .then, dividing by  gives: now, we take the square root.  (note that if , the rhs will be negative, so we must have .  moreover, note that  can be either positive or negative, and we must consider both values for the rhs as a result.)we thus have: note that this technically means the function does not have an inverse function, since there are two possible y-values for any x-value.  however, if we restrict the domain of the original function to the nonnegative reals, we can define the inverse as: read more on -