SOLUTION: PLEASE help me with these 2 problems as I have completed the other 28 problems on my College Algebra worksheet, but just cannot get these that deal with INFINITY or -INFINITY. Tha

Click here to see ALL problems on Functions

Question 97435: PLEASE help me with these 2 problems as I have completed the other 28 problems on my College Algebra worksheet, but just cannot get these that deal with INFINITY or -INFINITY. Thanks so much.
1. Find the domain of the given function. (If you need to use negative infinity or infinity, enter -INFINITY or INFINITY.)
K(v) = 4v^2 - 9/v^2 - v - 72
2. Write the domain of the rational function in interval notation as:
f(x) = 1/x - 11
(Type -INFINITY for -x or INFINITY for x, if needed.)
Thanks~ I do need this as soon as possible. I appreciate your help sooooo much.
Answer by jim_thompson5910(35256) (Show Source):
You can put this solution on YOUR website!
1.

Start with the given function

Set the denominator equal to zero

Factor the left side (note: if you need help with factoring, check out this solver)

Now set each factor equal to zero:

or

or Now solve for v in each case

Since or make the denominator equal to zero, that means we must exclude these values from the domain.

So our domain is: v is the set of all real numbers except or

Which looks like this in interval notation:

----------------------------------------------------------------------------------------

2.

Start with the given function

Set the denominator equal to zero

Add 11 to both sides

Combine like terms on the right side

So when , our denominator is zero. So we must exclude this value.

So our domain is: x is the set of all real numbers except

Which looks like this in interval notation: