Which values are NOT in the domain of the function?
f(x)
x +4
x2 – 25
O
A) x = -4,4
B) 2 = -5,4
C) x = -4,5
OD) X = -5,5

Respuesta :

Given:

The function is:

[tex]f(x)=\dfrac{x+4}{x^2-25}[/tex]

To find:

The values that are NOT in the domain of the given function.

Solution:

We have,

[tex]f(x)=\dfrac{x+4}{x^2-25}[/tex]

This function is a rational function and it is defined for all real values of x except the values for which the denominator is equal to 0.

Equate the denominator and 0.

[tex]x^2-25=0[/tex]

[tex]x^2=25[/tex]

Taking square root on both sides, we get

[tex]x=\pm \sqrt{25}[/tex]

[tex]x=\pm 5[/tex]

So, the values [tex]x=-5,5[/tex] are not in the domain of the given function.

Therefore, the correct option is D.