What is the domain of f(x)=(x-9)/(x^2-4x-21) ?

The domain of f(x)=(x-9)/(x^2-4x-21) is x 7

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

domain of f(x)=(x-9)/(x^2-4x-21)

domain

f (x) = \frac{x - 9}{x ^{2} - 4 x - 21}

x < - 3 or - 3 < x < 7 or x > 7

Interval Notation

(- \infty, - 3) \cup (- 3, 7) \cup (7, \infty)

Solution steps

Find undefined (singularity) points:

x = 7, x = - 3

The function domain

x < - 3 or - 3 < x < 7 or x > 7

What is the domain of f(x)=(x-9)/(x^2-4x-21) ?
The domain of f(x)=(x-9)/(x^2-4x-21) is x<-3\lor-3<x<7\lor x>7