Show all work to identify the asymptotes and zero of the function f of x equals 3 x over quantity x squared minus 9.

What is the value of x? enter your answer in the box. x = a right triangle with vertices labeled as a, b, and c. side c b is the base, and the top vertex is a. side a b contains a midpoint d. a line segment drawn from c to d bisects angle a c b into two parts labeled as a c d and b c d. angles a c d and b c d are marked with single arc. side a c is labeled as 3. base c b is labeled as 4. segment a d is labeled as 2.25. segment b d is labeled x.