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anonymous

  • one year ago

Find the derivative of f(x) = -12x2 + 9x at x = 6. -112.5 -135 -90 -108 @ganeshie8 @hero @dan815 @perl @pooja195 @nincompoop @CGGURUMANJUNATH @zepedrix @usukidoll

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  1. nincompoop
    • one year ago
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    use power rule

  2. anonymous
    • one year ago
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    how do i do that? can u show me step by step? @nincompoop

  3. nincompoop
    • one year ago
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    you can get the general derivative first and then apply at x=6 or you can apply it from the beginning

  4. UsukiDoll
    • one year ago
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    \[f(x) = -12x^2+9x \]

  5. nincompoop
    • one year ago
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    alright, guy what have you learned so far?

  6. nincompoop
    • one year ago
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    have you learned derivative by limit definition yet?

  7. anonymous
    • one year ago
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    no or maybe i did but i dont remember. can one of u show me step by step @UsukiDoll @nincompoop

  8. nincompoop
    • one year ago
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    okay do you know what a derivative is first?

  9. anonymous
    • one year ago
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    no @nincompoop

  10. nincompoop
    • one year ago
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    ahhhhh

  11. nincompoop
    • one year ago
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    do you know what a slope is?

  12. anonymous
    • one year ago
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    once i have f(x)=-12x^2+9(x) what would i do?

  13. nincompoop
    • one year ago
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    I can give you the general formula for power-rule, but it won't help you much in the long run if you have no clue what derivatives are.

  14. nincompoop
    • one year ago
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    so do you know what is slope?

  15. nincompoop
    • one year ago
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    I am asking a series of questions to see where is the proper place to begin.

  16. anonymous
    • one year ago
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    no i dont @nincompoop

  17. Astrophysics
    • one year ago
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    \[\frac{ d }{ dx } x^n = nx^{n-1}\] power rule

  18. nincompoop
    • one year ago
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    man...

  19. nincompoop
    • one year ago
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    laughing out loud

  20. UsukiDoll
    • one year ago
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    wow nin... don't be rude -_-

  21. nincompoop
    • one year ago
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    I'd use \(a \) instead of the coefficient n

  22. nincompoop
    • one year ago
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    whatever floats floats

  23. anonymous
    • one year ago
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    @UsukiDoll can u please help me

  24. nincompoop
    • one year ago
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    alright, I think we've got a problem here I am dumbfounded why you're doing derivative when you do not know what slopes are.

  25. nincompoop
    • one year ago
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    in any case, we can go ahead and start with slope in general

  26. nincompoop
    • one year ago
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    begin by our day-to-day language, slope pertains to the steepness of something think of a slide or a hill or anything that goes down or up, it will have a slope

  27. nincompoop
    • one year ago
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    now we can try to infuse a some math into the language

  28. Astrophysics
    • one year ago
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    Well I don't think you have to go that far nin, I'm sure OP knows what slope is and just needs to remember |dw:1436327588479:dw| one image will do wonders

  29. nincompoop
    • one year ago
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    I was just about to draw

  30. anonymous
    • one year ago
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    okay i already know this?

  31. nincompoop
    • one year ago
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    are you asking us or telling us?

  32. anonymous
    • one year ago
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    telling u

  33. nincompoop
    • one year ago
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    alright great! now we can move on to derivatives! laughing out loud

  34. Astrophysics
    • one year ago
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    But for your question, you find the derivative then plug in the value of x they've given you

  35. UsukiDoll
    • one year ago
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    sorry I'm with another user right now.

  36. nincompoop
    • one year ago
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    basically derivative pertains the slope at a particular instant

  37. nincompoop
    • one year ago
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    |dw:1436327777742:dw|

  38. nincompoop
    • one year ago
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    a good example of the instant that I am referring to is where one of the lines intersects at one point with the circle

  39. Astrophysics
    • one year ago
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    Jessica were you taught definition\[f'(x) = \lim_{h \rightarrow 0} \frac{ f(x+h)-f(x) }{ h }\] of derivative, I think that's what you have to use

  40. nincompoop
    • one year ago
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    now before we proceed, we must be able to identify and know about continuous functions

  41. nincompoop
    • one year ago
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    think of this portion as an algebra recap will you be able to tell us if the equation you're given is continuous or not?

  42. nincompoop
    • one year ago
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    if you're unsure, now is the time to learn them http://tutorial.math.lamar.edu/Classes/CalcI/CalcI.aspx

  43. nincompoop
    • one year ago
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    review on tangents with pretty awesome illustration http://tutorial.math.lamar.edu/Classes/CalcI/Tangents_Rates.aspx

  44. nincompoop
    • one year ago
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    let us know when you've digested the concept of tangents and derivatives because the next part will be testing your algebra skills with derivatives using limit-definition.

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