Find the domain of each of the following real valued functions of real variable: `f(x)=(2x+1)/(x^2-9)`

Explanation

As we know that, f (x) is defined for all real values of x, except for the case when

`x^2 – 9 = 0`

` x^2 – 9 = 0`

` x^2 – 3^2 = 0 `

`(x + 3)(x – 3) = 0 `

`x + 3 = 0 or x – 3 = 0 `

`x = +-3 `

∴ Domain of `f = R – {–3, 3}`