Find the domain of the function fx Squareroot 5 4xx2 81 a

Find the domain of the function f(x) = Squareroot 5 - 4x/x^2 - 81 and write your answer in interval notation. Domain:

f(x)=sqrt(5-4x)/x²-81

Its a rational expression and the denominator cant be zero .

And at x=9,-9 the denominator becomes zero.

So we need to exclude these values from domain

The numerator have square root. And square root terms must be greater than 0.

5-4x>=0

x<=5/4

Therefore domain is

(-infinity,-9)U(-9,5/4]