Algbrea 2 Math Could someone please help me

Question

c(x)=-3/over x^2-1

 

 

The domain is  ??   Answer in interval notation

Answer 1

The denominator cannot be zero. 

 

So, x² -1 ≠ 0

Then,

      x ≠ ±1

 

So, the answer is 

 

(-∞,-1) ∪ (-1,1) ∪ (1,∞)

Answer 2

The basic rule is that we cannot divide by zero, thus  the denominator x^2 - 1 cannot = 0

 

Since both x = (-1)^2 and x = 1^2 would both give a value of zero in the denominator, x cannot = -1 or 1

 

Thus the domain of x is all real numbers except -1 or 1

 

In interval notation this would be written as (-infinity,-1) U (-1,1) U (1,infinity)

 

Note:  Use the "sideways 8" infinity sign in place of the word in the answer

Note:  We do not use the inclusive [ sign when denoting values out to infinity as said value can never be obtained, thus

          the open (  and  ) in the endpoints of the answer denoting that infinity is not actually included in the answer.

 

Answer 3

( -∞. -1) U (-1, +1), (1,+∞)