Question

When looking at the rational function f of x equals the quantity x minus one times the quantity x plus two times the quantity x plus four all divided by the quantity x plus one times the quantity x minus two times the quantity x minus four, Bella and Edward have two different thoughts. Bella says that the function is defined at x = –1, x = 2, and x = 4. Edward says that the function is undefined at those x values. Who is correct? Justify your reasoning.

Answer 1

$\Large f(x) = \frac{(x - 1)(x + 2)(x + 4)}{(x + 1)(x - 2)(x - 4)}$

$\Large f(x) = \frac{(x - 1)(x + 2)(x + 4)}{(x + 1)(x - 2)(x - 4)}$

$\Large f(x) = \frac{(x - 1)(x + 2)(x + 4)}{(x + 1)(x - 2)(x - 4)}$

$\Large f(x) = \frac{(x - 1)(x + 2)(x + 4)}{(x + 1)(x - 2)(x - 4)}$

$\Large f(x) = \frac{(x - 1)(x + 2)(x + 4)}{(x + 1)(x - 2)(x - 4)}$

 

Bella says that the function is defined at x = –1, x = 2, and x = 4 so Bella is wrong since the result is undefined because we cannot divide by zero Therefore, Edward is correct.