What is the domain and range of this relation?

Question

f(x) = 2x + 7/x^2 - 9 

f(3) = ? 

Answer 1

The function

Change f (x ) to y .

We know that all possible values of x  is domain of a function.

A rational function is simply fraction and in a fraction the denominator cannot be equal to 0 because it would be undefined.

To find which number make the fraction undefined create an equation where the denominator is not equal to zero.

Domain is

The range of the function  is all Real numbers.