Results 1 to 10 of 10

Math Help - cubic equation curve

  1. #1
    Newbie
    Joined
    Apr 2008
    Posts
    4

    Exclamation cubic equation curve

    Hello all, I searched the web for this answer, could not find it, as such i turn to you all smart people. I have read the thread
    Cubic equation from 4 coordinates

    However i have no idea what to do, if someone can help me before the end of April would be appreciated.

    Ok the question is:

    *graph* coordinates that can be known, (0,0) (1,8) (2,6) (3,0) (4,-4) (5,0) and (6,18)

    Now the actual question is to find accurately the area enclosed by this curve and the x-axis, but to do it accurately, one would have to use definite integral. However i have used the Trapezium Method and the Triangle area method to kinda get an area, but the question after this one requires this one to be dead accurate

    i have battled with it for some time; I have nooooo cooking clue of how to do this....

    Please help...
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by KarrotBear View Post
    Hello all, I searched the web for this answer, could not find it, as such i turn to you all smart people. I have read the thread
    Cubic equation from 4 coordinates

    However i have no idea what to do, if someone can help me before the end of April would be appreciated.

    Ok the question is:

    *graph* coordinates that can be known, (0,0) (1,8) (2,6) (3,0) (4,-4) (5,0) and (6,18)

    Now the actual question is to find accurately the area enclosed by this curve and the x-axis, but to do it accurately, one would have to use definite integral. However i have used the Trapezium Method and the Triangle area method to kinda get an area, but the question after this one requires this one to be dead accurate

    i have battled with it for some time; I have nooooo cooking clue of how to do this....

    Please help...
    You can find the area of the polygon defined by the given vertices and the axes, however without specifying what type of curve is to go through the points there is no unique area definable from a set of points.

    RonL
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Moo
    Moo is offline
    A Cute Angle Moo's Avatar
    Joined
    Mar 2008
    From
    P(I'm here)=1/3, P(I'm there)=t+1/3
    Posts
    5,618
    Thanks
    6
    Hello CB,

    He said it was a cubic thing, looks like polynomial of degree 3..
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by Moo View Post
    Hello CB,

    He said it was a cubic thing, looks like polynomial of degree 3..
    No he did not say it was a cubic, he read a thread about fitting a cubic, that is not the same thing.

    If he wants a cubic then he should say so.

    RonL
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Moo
    Moo is offline
    A Cute Angle Moo's Avatar
    Joined
    Mar 2008
    From
    P(I'm here)=1/3, P(I'm there)=t+1/3
    Posts
    5,618
    Thanks
    6
    He already said, in his other thread, and in the live chat
    Follow Math Help Forum on Facebook and Google+

  6. #6
    MHF Contributor
    Joined
    Apr 2008
    Posts
    1,092
    The cubic equation
    x(x-3)(x-5)=0

    seems to satisfy your conditions. If you multiply that out you get
    x^3-8x^2+15x=0
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by Moo View Post
    He already said, in his other thread, and in the live chat
    What other thread? (I expect topsquark deleted it)

    And any amplification posted in chat is wasted as most people who might help will never read it.

    RonL
    Follow Math Help Forum on Facebook and Google+

  8. #8
    Moo
    Moo is offline
    A Cute Angle Moo's Avatar
    Joined
    Mar 2008
    From
    P(I'm here)=1/3, P(I'm there)=t+1/3
    Posts
    5,618
    Thanks
    6
    Yep, it has been deleted... I know for the chat, I just wanted to tell you that it was a cubic equation
    Follow Math Help Forum on Facebook and Google+

  9. #9
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by Moo View Post
    Yep, it has been deleted... I know for the chat, I just wanted to tell you that it was a cubic equation
    OK, if it is a polynomial of degree <7, then the 7 point Newton-Cotes formula will give the exact integral.

    RonL
    Follow Math Help Forum on Facebook and Google+

  10. #10
    Newbie
    Joined
    Apr 2008
    Posts
    4

    Wink Thank you everyone :)

    Sorry for double posting/ spamming (if you really can call it that) didnt know it was against rules.

    Well yes it is actualy a cubic function, we're in a public school so what do you expect from questions, they only hint at what it is awell

    thank you everyone
    I have a massivly COOOOL graphics calculator that did it for me, like i was so stressing and then the teachers like " oh and this is how you get the formula for a cubic"


    Icemanfan, how did you find that equation? because i wanna know how you did it

    Captian Black your tooo smart, ive got a physics teacher like you knows everything in the world i rekon :P

    awell thank you all
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Parametric Cubic Curve Middle Coordinates
    Posted in the Advanced Applied Math Forum
    Replies: 1
    Last Post: October 14th 2009, 07:56 AM
  2. Parametric Cubic Curve
    Posted in the Advanced Math Topics Forum
    Replies: 1
    Last Post: October 12th 2009, 07:09 PM
  3. Parametric Cubic Curve Equation
    Posted in the Calculus Forum
    Replies: 0
    Last Post: October 12th 2009, 11:08 AM
  4. Parametric Cubic Curve Points and Coordinates
    Posted in the Advanced Applied Math Forum
    Replies: 1
    Last Post: October 11th 2009, 11:37 AM
  5. Replies: 8
    Last Post: October 8th 2007, 04:29 PM

Search Tags


/mathhelpforum @mathhelpforum