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← How do we find x intercepts - College Algebra

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Showing Revision 2 created 05/25/2016 by Udacity Robot.

  1. Now, you might be wondering why on Earth this is helpful at all, well, remember,
  2. what we're trying to do here. Since we can't factor this expression, we need a
  3. different way to find the x-intercepts. Here, we can tell that we're getting
  4. close to being able to do that. At some point, we want to set y equal to zero,
  5. and now we only have x written in one spot in our equation, rather than in two.
  6. We know how to take square roots, so I feel like we're getting pretty close. At
  7. this point, we need to think about the difference of squares again. Remember
  8. that if we have a squared minus b squared, we can factor this as a minus b times
  9. a plus b. Here, we have one term that's clearly squared, so maybe we can use
  10. this technique to help us out. Now, 6 doesn't look like a squared number, but
  11. that doesn't really matter. We can stil,l of course, take the square root of 6
  12. and get a number. It may not be an integer but it is a real number. What I would
  13. like you do now is keeping all that in mind, write out the two factors in this
  14. form that we have coming from this expression right here. This is going to look
  15. pretty different from anything we worked with before and you may not think it
  16. looks very pretty but just go with it, this is going to be super, super useful
  17. in everything we have coming up.