Math QUESTION PLZZ HELP!!! Domain of F?

Question

If f(x)= 3x^2 - 4x - 5 / x^2 - 9 ......What is the domain of the Function.

Answer 1

f(x) = (3x^2 - 4x - 5) / (x^2 - 9)

For rational (fraction) functions and finding the domain, the only thing you have to worry about is the denominator NOT being equal to 0.

To find the domain, you determine what values make the denominator 0, and note that x cannot equal that value (or values). Therefore, equate the denominator to 0.

x^2 - 9 = 0

Now, solve for x.

(x - 3)(x + 3) = 0, therefore
x = {3, -3}

The domain of this function, in set notation is
{x | x is NOT equal to 3 and x is NOT equal to -3}

In interval notation,

(-infinity, -3) U (-3, 3) U (3, infinity)

{Note: we use round brackets to show that -3 is not included.}

Answer 2

1

Answer 3

take the factor of dinominator = x^2-9 and equal to zero

= (x-3) * (x+3) = 0

Hence x = 3, -3

Domain for the function f(x) = 3, -3,
Note that domain is alwaya a real number hence it is 3

Answer 4

set the denominator (the stuff on the bottom) equal to zero and solve for X. The domain is all real numbers when X does not equal what you got for your answer. Don't forget that since you have to find the square root, it will be plus or minus.

so yes, the answer is 3, -3

Answer 5

all real numbers except 3 and -3