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anonymous

  • one year ago

???

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  1. welshfella
    • one year ago
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    |dw:1440801196586:dw|

  2. anonymous
    • one year ago
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    Yes thats it

  3. anonymous
    • one year ago
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    I derived it and got f'(x) = 3x^(-2/3) + 6x^(1/3)

  4. welshfella
    • one year ago
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    yes thats right

  5. welshfella
    • one year ago
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    no you need to find the zeroes of this

  6. anonymous
    • one year ago
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    Well this is what I have so farf'(x) = 3x^(-2/3) + 6x^(1/3) f"(x) = -2x^(-5/3) + 2x^(-2/3) f'(x)= -(1/2) f"(-1/2) = 6*2^(2/3)

  7. anonymous
    • one year ago
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    Am I on the right track?

  8. welshfella
    • one year ago
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    the zero of f'(x) = -0.5

  9. welshfella
    • one year ago
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    and its a minimum yep

  10. anonymous
    • one year ago
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    Do I need the last step that I did or is that unnecessary?

  11. welshfella
    • one year ago
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    no you need the last step - the second derivative is positive indicating a minimum

  12. welshfella
    • one year ago
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    The function might have some inflection points though ( Non horizontal ones). I cant remember how to find those to be honest!

  13. welshfella
    • one year ago
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    I'll graph it to see. Yes there is one close to x = 0

  14. anonymous
    • one year ago
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    Okay so I solve the last step and then find the inflection points?

  15. welshfella
    • one year ago
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    maybe cant remember I'd have to look that up

  16. anonymous
    • one year ago
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    Okay

  17. welshfella
    • one year ago
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    i think you equate f" to zero and solve

  18. anonymous
    • one year ago
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    Thats it?

  19. welshfella
    • one year ago
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    do you get x = 1 for that?

  20. welshfella
    • one year ago
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    now you have to look for concavity each side of this point

  21. anonymous
    • one year ago
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    Let me see

  22. welshfella
    • one year ago
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    - no needn't do that They just want the x coordinate of the point of inflection

  23. welshfella
    • one year ago
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    x = 0 will satisfy f" = 0 as well . That is the one i see on the graph.

  24. anonymous
    • one year ago
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    So is it done as it?

  25. welshfella
    • one year ago
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    i think so . there's a definite point of inflection at x =0 on the graph

  26. anonymous
    • one year ago
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    Okay thank you!!! So x=0 and x=-.5 are my answers?

  27. welshfella
    • one year ago
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    cant see one at x = 1 though

  28. welshfella
    • one year ago
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    -0.5 is a minimum x = 0 is a point of inflection

  29. anonymous
    • one year ago
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    Okay thank you!

  30. welshfella
    • one year ago
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    yw

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