Monday, February 22, 2010

Simplifying Radical Expressions

My Algebra I students are having lots of problems with simplifying radical expressions. It seems that they have run across a concept that eludes them. I am posting about this topic to provide several more examples.

√18

First, we find the prime factorization of 18. If you need help with this concept, go here.

√18 = √(2•3•3)

Since the 3 is repeated twice, we can pull it out from under the square root symbol. Therefore,

√18 = 3√2

Now my students would be asking what happens if you have variables?

√24x3y2

√24x3y2 = √(2•2•2•3•x•x•x•y•y)

Pull out everything that is repeated twice - 2, x, y. Leave everything else under the radical symbol.

2xy√(6x)

Some other places to visit for more details on this concept are here and here and here.

If you are one of my students and would like some extra credit, please visit those sites and comment here on whether or not they were helpful.
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25 comments:

  1. AnonymousApril 21, 2009 at 10:26 AM

    Mrs. Bentley
    I figured out more about the perfect squares and how to start the problems and how to reduce em to the lowest term

    J Harris

    ReplyDelete
  2. Josh JApril 21, 2009 at 10:27 AM

    do u use perfect squares to simplify radical equations

    ReplyDelete
  3. J ClarkApril 21, 2009 at 4:32 PM

    I understood it to begin with, but now that i look at these other sites and see how other people are doing it i have learned how to do it different ways. I thought it to be helpful and i think i got this down to a T.

    ReplyDelete
  4. D JohnsonApril 22, 2009 at 4:22 PM

    this helps out alot it breaks it down and explains it better. i think i got how to do it now.

    ReplyDelete
  5. Angelica LApril 22, 2009 at 6:44 PM

    i been having problems with when you simplify once you can still simplify smaller and it help me with that.

    ReplyDelete
  6. S LEWISApril 23, 2009 at 9:10 AM

    i knew how to do it but there was one part that i did not know how to do but i think i get it since i looked at this web site. thank you for posting this on here MRS BENTLEY

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  7. K BrunsonApril 23, 2009 at 10:06 AM

    I get how to do these ones but its the ones were you add and subtract radicals and the fraction ones that confuse me

    ReplyDelete
  8. j davidsonApril 23, 2009 at 10:33 AM

    J DAVIDSON. I used 2 have very bad problems with radicals. but since made a 100 and studied the radical rules while i was suspended i really didnt need the extra credit sites. but when i looked at the it sites helped me understand the concept of simplflying radicals and gave me more tips and hints about answering the tough problems of radicals.

    ReplyDelete
  9. Brittany JApril 23, 2009 at 10:55 AM

    i understand now how to do it this page helped me a whole lot thanks a million Mrs. Bentley

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  10. AnonymousApril 23, 2009 at 12:29 PM

    mrs. bentley
    I now know that when simplifying radicals that you should always go for the biggest number first to simplify it.
    R NeSmith

    ReplyDelete
  11. AnonymousApril 23, 2009 at 5:01 PM

    ok, I get it now. Before I was always trying to find a shortcut and that just confused me more. Now that i looked at it, I do beleive Im going to be able to do it step by step, and because of this site Ill be able to do each problem without looking at an already completed problem to know how to do it.
    H. Abbott

    ReplyDelete
  12. s lewisApril 24, 2009 at 9:17 AM

    i finlly got it because this website explains it all

    ReplyDelete
  13. K.LangstonApril 24, 2009 at 9:21 AM

    To start off i didnt understand this alot and may have been something to do with me missing a few days of school due to i was really sick. However, reading this information,and really thinking about it i believe i do understand the materials now!!
    K.langston

    ReplyDelete
  14. K Hicks.April 24, 2009 at 9:30 AM

    This website was realy helpful when it comes to breaking down the problem but i thought there was more to it? & i'll use the information to take the test..does this website hold all the info we need?? thanks again :)

    k.hicks

    ReplyDelete
  15. Maggie EApril 24, 2009 at 10:31 AM

    To begin with i didnt understand it but once i looked at the web site it explained it all...
    M. Ellis

    ReplyDelete
  16. harleywApril 24, 2009 at 10:32 AM

    i didnt understand when we was working it in class.but this website helped me understand it better.

    h.white

    ReplyDelete
  17. AnonymousApril 24, 2009 at 10:33 AM

    these sites helped me understand how to simplify radicals more.

    B.Baggett

    ReplyDelete
  18. cynthia mApril 24, 2009 at 10:34 AM

    i knew how to do most of this but it was sometimes confusing..seeing these sites has helped me see things clearer and now i understand it way better.. c.mendez

    ReplyDelete
  19. AnonymousApril 24, 2009 at 10:35 AM

    when we first started simplifying radicals, i was like i want be able to do this. but i know enough now to get me by. thanks to this website

    ReplyDelete
  20. Greg BApril 24, 2009 at 10:39 AM

    this site was helpful i found out i was doin a couple of things wrong but i think i got it now

    ReplyDelete
  21. C HillApril 24, 2009 at 10:49 AM

    simplifing radicals helped me by understandin how uput all the factorizations in it in another step i didnt understand it at first i was guessin

    ReplyDelete
  22. thomas bApril 24, 2009 at 10:49 AM

    i finaly figured out hw to work the prime factorization problems with a veriable

    ReplyDelete
  23. wesleyApril 24, 2009 at 10:52 AM

    i learned alot from this website i learned how to break down the problen and that was what i was havin problems with

    ReplyDelete
  24. AnonymousApril 27, 2009 at 9:21 AM

    This website has told me a lot on how to Simplifying Radical Expressions. I didn't understand how to do it at firs but now I do. :]
    A.Sutton

    ReplyDelete
  25. AnonymousSeptember 13, 2009 at 8:12 PM

    what about cube roots?

    ReplyDelete

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