Results 1 to 5 of 5

Math Help - Tangent line to the curve

  1. #1
    Member
    Joined
    May 2009
    Posts
    93

    Lightbulb Tangent line to the curve

    Find the equation for the to the given curve at the point where x = X₀

    y=(x^2+3x-1)(2-x); X₀=1

    I found the first derivative which came out to:

    -x^2-3x+(2-x)(2x+3)+1
    simplified to:
    -3x^2-2x+7

    then I set f( X₀)=1 to f( X₀)=(1)=2

    Then I plugged it in my equation:

    -3(1^2)-2(1)+7=2

    I'm not sure if I'm doing it right and i'm not sure how to finish it. Thanks!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor Amer's Avatar
    Joined
    May 2009
    From
    Jordan
    Posts
    1,093
    typo
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor Amer's Avatar
    Joined
    May 2009
    From
    Jordan
    Posts
    1,093
    Quote Originally Posted by lisa1984wilson View Post
    Find the equation for the to the given curve at the point where x = X₀

    y=(x^2+3x-1)(2-x); X₀=1

    I found the first derivative which came out to:

    -x^2-3x+(2-x)(2x+3)+1
    simplified to:
    -3x^2-2x+7

    then I set f( X₀)=1 to f( X₀)=(1)=2

    Then I plugged it in my equation:

    -3(1^2)-2(1)+7=2

    I'm not sure if I'm doing it right and i'm not sure how to finish it. Thanks!
    y(1)=3
    y'=-3x^2-2x+7
    y'(1)=2
    (y-3)=2(x-1)
    this is the equation of the curve
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Member
    Joined
    May 2009
    Posts
    93
    I don't want to be a pain but how did you get the answers! I have a few others like this and I want to know how to do the rest.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Senior Member Spec's Avatar
    Joined
    Aug 2007
    Posts
    318
    k=\frac{y-y_0}{x-x_0} and use the fact that the tangent k=f'(x_0)
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Tangent line to a curve.
    Posted in the Calculus Forum
    Replies: 1
    Last Post: June 19th 2011, 07:53 AM
  2. [SOLVED] Tangent line to the curve.
    Posted in the Calculus Forum
    Replies: 2
    Last Post: March 16th 2010, 07:16 PM
  3. Replies: 5
    Last Post: November 4th 2009, 07:49 PM
  4. Tangent line to curve
    Posted in the Calculus Forum
    Replies: 2
    Last Post: October 14th 2009, 05:43 PM
  5. Tangent line to a given curve.
    Posted in the Calculus Forum
    Replies: 2
    Last Post: September 2nd 2009, 08:38 AM

Search Tags


/mathhelpforum @mathhelpforum