Quantcast

A community for students. Sign up today!

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

mathcalculus

  • one year ago

help :( locate all critical points ( both types ) of h(x)= radical 8-6*x^2 The critical point(s) is (are) .

  • This Question is Closed
  1. MoonlitFate
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So the function h(x) = \[\sqrt{8-6x^2}\] , is that right? By critical points, do you mean relative maxima / minima?

  2. mathcalculus
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yes

  3. mathcalculus
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i mean x and y

  4. mathcalculus
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    critical points..

  5. MoonlitFate
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Oh, okay. First of all, do you know how to take the derivative of h(x)?

  6. mathcalculus
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    so far im here: -12x/ 2 radical 8-6x^2

  7. MoonlitFate
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    The derivative of h(x) is: \[\frac{ -6x }{ \sqrt{8-6x ^{2}} }\]

  8. MoonlitFate
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    The next step, is finding where f'(x) = 0 or is undefined, since that's going to find the critical points of f. And you can use those to form intervals to test for minima and maxima.

  9. MoonlitFate
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    So, you're going to set f'(x) to 0 and solve for x.

  10. mathcalculus
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    okay makes sense... then to find the critical points i equal that to zero... and just solve for x?

  11. mathcalculus
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh so wait, i don't equal it to zero.... i plug in zero into x?? and from the original problem i plug int the x when i find that out?

  12. MoonlitFate
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\frac{ -6x }{ \sqrt{8-6x ^{2}} } = 0 \] \[(\sqrt{8-6x ^{2}}) *\frac{ -6x }{ \sqrt{8-6x ^{2}} } = 0 \sqrt{8-6x ^{2}}\] \[-6x = 0\] \[x=0\]

  13. MoonlitFate
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Also f is undefined when:\[x = \pm \frac{ -2\sqrt{3} }{ 3 }\] and since there can't be a negative square root for the denominator, the domain of f is \[[x = \pm \frac{ -2\sqrt{3} }{ 3 }]\] , so you will use that along with 0 to make test intervals.

  14. mathcalculus
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I got zero as well... not how do i find y

  15. mathcalculus
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i plugged in zero into the normal question... and got 2 radical 2

  16. mathcalculus
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    answer: (0,2 radical 2) is wrong://

  17. MoonlitFate
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Gah, I was doing something more complicated. Ignore the part about test intervals, sorry. :(

  18. mathcalculus
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    its okay can we do after we find the x

  19. mathcalculus
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    the y..

  20. MoonlitFate
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Plug in the critical numbers into the f(x).

  21. mathcalculus
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i plug in 0 in the original function? to find y right

  22. MoonlitFate
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Yes, sorry. Working it out over here, too. ^^;

  23. mathcalculus
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[2\sqrt{2}\]...

  24. mathcalculus
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    i keep getting wrong :(

  25. mathcalculus
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ?

  26. MoonlitFate
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[f(0) = \sqrt{8-6(0)^2} = \sqrt{8}= 2\sqrt{2}\]

  27. MoonlitFate
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I was actually getting kinda confused, and I ended up graphing it to check.

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

    Search OpenStudy
    • 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.