## anonymous one year ago Jake says that the function is defined at x = –1, x = 3, and x = 4. Yoe says that the function is undefined at those x values. Who is incorrect? Justify your reasoning.

1. anonymous

@Michele_Laino

2. anonymous

f(x)=(x-1)(x+2)(x+4)/(x+1)(x-2)(x-4)

3. anonymous

do you understand the function I wrote or should I draw i?

4. Michele_Laino

from the text of your problem I can write this expression for function f(x): $\Large f\left( x \right) = \frac{{\left( {x - 1} \right)\left( {x + 2} \right)\left( {x + 4} \right)}}{{\left( {x + 1} \right)\left( {x - 2} \right)\left( {x - 4} \right)}}$

5. Michele_Laino

now we can not divide by zero, so we have to exclude those values of x, such that: $\Large \begin{gathered} x + 1 = 0 \hfill \\ x - 2 = 0 \hfill \\ x - 4 = 0 \hfill \\ \end{gathered}$ in other words we have to be certain that the denominator is not equal to zero

6. anonymous

ok, i see

7. Michele_Laino

for example if I solve the first equation, I get: x=-1 so I have to exclude that value

8. Michele_Laino

If I solve the second equation, I get: x=2 again, I have to exclude the value x=2

9. Michele_Laino

similarly for third equation: x-4=0 which gives: x=4, and i have to exclude that value

10. anonymous

ok:) I understand

11. Michele_Laino

ok!

12. anonymous

So the answer would be? @Michele_Laino

13. Michele_Laino

Edward is right!

14. anonymous

ok:) Thanks!!!

15. Michele_Laino

:)