SOLUTION: Find all numbers which the rationnal expresson is undefined. p^3-4p divided by p^2-49. i started to factor the top p(p^2-4)= (p-2)(p+2) then the bottom (p-7)(p+7). I think

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Question 156593: Find all numbers which the rationnal expresson is undefined.
p^3-4p divided by p^2-49.
i started to factor the top p(p^2-4)= (p-2)(p+2)
then the bottom (p-7)(p+7).

I think im factoring and not answering the question. So many rules and formulas im getting mixed up.
Hel

Found 2 solutions by jim_thompson5910, Earlsdon:
Answer by jim_thompson5910(35256) (Show Source):
You can put this solution on YOUR website!
Remember you CANNOT divide by zero (ie something like is NOT possible). So this means that if there are values of "p" that make the denominator equal to zero, then these "p" values make the expression undefined.

Set the denominator equal to zero

Factor the left side

or Set each factor equal to zero

or Solve for "p" for each case

So if or , then the denominator is zero. So either or will make the expression will make the expression undefined.

note: the numerator plays no part in determining undefined values since 0 in the numerator is possible.

Answer by Earlsdon(6294) (Show Source):
You can put this solution on YOUR website!
Given:

Find the values of p for which the given expression is undefined.
An expression is "undefined" if its denominator is zero, so you want to find which values of p will make the denominator zero. You can leave the numerator as is and concentrate on the denominator:
Factor the denominator. You have done this correctly!

Now look at the factors in the denominator to see what values of p will make either factor zero.
, so is an "excluded" value.
, so is an "excluded" value.
So that p = 7 and p = -7 are the values of p that will render the expression "undefined"