Question

What values of x must be excluded from the domain of

f(x) = x + 7
_____
x^2 - 5x -6


A ) x =1 and x =-6

B ) x = -1 and x=6

C ) x= -7

D ) x = 2 and x = 3

E ) x = -6 and x = -7

Answer 1

c

Explanation:

-2 & 6

Answer 2

B) x = -1 and x = 6

Explanation:

The values that must be excluded from the domain are the values for which f(x) is undefined. Those values are the ones that make the denominator be zero.

We can find the zeros of the denominator by factoring.

... x² -5x -6 = (x +1)(x -6)

The product is zero when either factor is zero, so when x=-1 or x=6.