Quantcast

A community for students. Sign up today!

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

CoffeeEyes

  • 2 years ago

Help? Please? 4/ 5 + √2

  • This Question is Closed
  1. PhoenixFire
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    What do you want done?

  2. CoffeeEyes
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I need to rationalize the denominator. I have no idea what the steps are. I read my text book, but I'm so confused.

  3. tkhunny
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Is it \[\frac{4}{5+\sqrt{2}}\]

  4. PhoenixFire
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \[4 \over {5+\sqrt{2}}\] so you multiply both the numerator and denominator by the conjugate of the denominator. \[5+\sqrt{2}\] conjugate is \[5 - \sqrt{2}\] so you get \[(5+\sqrt{2})(5-\sqrt{2})\] and as you know \[(a+b)((a-b)=a^2-b^2\] So the denominator becomes \[5^2-(\sqrt{2})^2=25-2=23\] Leaving you with \[{{4(5-\sqrt{2})} \over 23}={{20-4 \sqrt{2}} \over 23}\]

  5. tkhunny
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @op Please do a little better with your notation if this is correct. If you mean the expression that has been the target of this worked exercise, you have not written wat you intended. 4 / 5 + sqrt(2) = \[\frac{4}{5}+\sqrt{2}\] 4 / (5 + sqrt(2)) = \[\frac{4}{5+\sqrt{2}}\] Always remember your Order of Operations. Use parentheses to clarify meaning.

  6. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Ask a Question
Find more explanations on OpenStudy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.